Development and Verification of a Diagnostic Technology for Waste Battery Deterioration Factors.

We defined four major deterioration factors (electrolyte loss (EL), lithium loss (LL), lithium precipitation (LP), and compound deterioration (CD)). Then, we derived eleven key performance indicators (KPIs) for comparative analysis. After that, we fabricated three deteriorated cells for each of three deterioration factors (EL, LL, and LP) and one cell with CD (for verification) with four individual (dis)charging experiment manuals. The two major contributions of this study are the performance of 1) trend analysis to determine a suitable diagnostic metric by inspecting the eleven KPIs and 2) comparison analysis of V o c v , t ' ' ${{V}_{ocv,t}^{{ {^\prime} {^\prime}}}}$ and V o c v , t , s i m ' ' ${{V}_{ocv,t,sim}^{{ {^\prime} {^\prime}}}}$ to verify the effectiveness of utilizing V o c v , t ' ' ${{V}_{ocv,t}^{{ {^\prime} {^\prime}}}}$ as a real-time deterioration diagnostic factor using a concept of model-in-the-loop simulation. The results show that 1) V o c v , t ' ' ${{V}_{ocv,t}^{{ {^\prime} {^\prime}}}}$ has the most conspicuous trendline tendency among the eleven comparison targets for all four major deterioration factors, and 2) the angle difference between the two trends of V o c v , t ' ' ${{V}_{ocv,t}^{{ {^\prime} {^\prime}}}}$ and V o c v , t , s i m ' ' ${{V}_{ocv,t,sim}^{{ {^\prime} {^\prime}}}}$ lies within a minimum of 9° and a maximum of 43° (with a 10 4 ${{10}^{4}}$ sscale on the x-axis and a 10 - 7 ${{10}^{-7}}$ scale on the y-axis for a clear trend line analysis). From this, we can conclude that the trendline-based real-time deterioration analysis employing V o c v , t ' ' ${{V}_{ocv,t}^{{ {^\prime} {^\prime}}}}$ may be practically applicable to a limited extent.

Optimal Synthesis and Application of a Si-Ti-Al Ternary Alloy as an Anode Material for Lithium-Ion Batteries.

The development of novel anode materials for high energy density is required. Alloying Si with other metals is a promising approach to utilize the high capacity of Si. In this work, we optimized the composition of a Si-Ti-Al ternary alloy to achieve excellent electrochemical performance in terms of capacity, cyclability, and rate capability. The detailed internal structures of the alloys were characterized through their atomic compositions and diffraction patterns. The lithiation process of the alloy was monitored using real-time scanning electron microscopy, revealing that the mechanical stability of the optimized alloy was strongly enhanced compared to that of the pure silicon material.

Results of a 10-year hearing screening using automated auditory brainstem response in newborns: The two-step AABR method.

OBJECTIVES: Approximately 1-6 in every 1000 children are born with hearing loss. An automated auditory brainstem response (AABR) test is essential for screening newborns for abnormal hearing. At the tertiary hospital, we have been using a two-step AABR protocol for newborn hearing assessment since 2005. This study aimed to report the 10-year hearing screening results of newborns at the institution, and prove the efficacy of the two-step AABR protocol. METHODS: From August 2005 to January 2015, 3059 newborns were screened through AABR testing using the MASTER ABaer system. The first screening test was performed after the first 24 h of life. If a newborn was referred, the test was performed within 1 month after discharge from the hospital. The results were regarded as pass when the point optimized variance ratio was >3.5, using a stimulus level of 35 dB HL. When newborns were referred for the second AABR, they received follow-up tests including tympanometry, ABR, auditory steady-state response, and otoacoustic emission within 3 months. RESULTS: A total of 3059 newborns underwent newborn hearing screening tests over a period of 10 years. One hundred and twenty (3.9%) newborns were referred with the initial AABR, and 104 (3.4%) were referred with a subsequent AABR. Of the newborns, 42 (1.37%) were confirmed to have a bilateral hearing impairment. CONCLUSIONS: It is known that the referral rate for the AABR test is 3-4%, as recommended by the Joint Committee on Infant Hearing. Our data showed a referral rate of 3.4%. The two-step AABR test has been useful for screening hearing loss in newborns at tertiary hospital.

Effects of Glycemic Control on Hearing Outcomes in Diabetes Patients With Idiopathic Sudden Sensorineural Hearing Loss.

OBJECTIVE: This study aimed to analyze the effects of glycemic control on the hearing outcomes of type 2 diabetes patients with idiopathic sudden sensorineural hearing loss (ISSHL). METHODS: Type 2 diabetes patients with ISSHL were enrolled. All patients were admitted for 5 days and received systemic corticosteroid treatment. Patients were divided into groups according to their degree of glycemic control pre- (glycosylated hemoglobin) and post- (mean blood glucose) onset of ISSHL. Demographic, audiometric, and hearing outcome data were analyzed. Furthermore, a multivariate analysis was performed to determine the prognostic factors affecting the hearing outcomes in these patients. RESULTS: One hundred forty-four patients were enrolled. The hearing recovery rates were as follows: complete recovery, 19%; partial recovery, 15%; slight improvement, 22%; and no improvement, 44%. Initial hearing levels and diabetes duration were significantly higher in the pre-onset poor-controlled group (glycosylated hemoglobin ≥ 7.0%) than those in the well-controlled group. The hearing recovery rates did not differ significantly pre- or post-onset. In a multivariate analysis, duration from hearing loss onset to treatment, presence of vertigo, and initial hearing level were negative prognostic factors that affected hearing recovery. CONCLUSION: The degree of pre- or post-onset glycemic control did not affect hearing outcomes in patients with ISSHL and type 2 diabetes. Therefore, the administration of systemic corticosteroid is required for diabetes patients with ISSHL within allowable blood glucose levels.

In Situ Observation of the Effect of Accelerating Voltage on Electron Beam Damage of Layered Cathode Materials for Lithium-Ion Batteries.

Electron beam damage from transmission electron microscopy of layered lithium transition-metal oxides is a threshold phenomenon that depends on the electron beam energy, which we demonstrate in this study by varying the accelerating voltage of a scanning transmission electron microscope. The electron beam irradiation experiment shows that Ni in LiNiO2 has much lower threshold energy for displacement than Co in LiCoO2, which is supported by DFT calculations predicting that Ni has lower migration energy. The transition-metal ions are reduced from the oxidation state of +3 to +2 during migration from their original positions to the lithium sites, and Ni is more easily reduced than Co because of its electronic configuration. In addition, the high-energy electron beam induces oxygen release, which is another symptom of degradation of materials that occurs more strongly in Ni-containing materials with ion displacement.

Triggered reversible phase transformation between layered and spinel structure in manganese-based layered compounds.

Irreversible phase transformation of layered structure into spinel structure is considered detrimental for most of the layered structure cathode materials. Here we report that this presumably irreversible phase transformation can be rendered to be reversible in sodium birnessite (NaxMnO2·yH2O) as a basic structural unit. This layered structure contains crystal water, which facilitates the formation of a metastable spinel-like phase and the unusual reversal back to layered structure. The mechanism of this phase reversibility was elucidated by combined soft and hard X-ray absorption spectroscopy with X-ray diffraction, corroborated by first-principle calculations and kinetics investigation. These results show that the reversibility, modulated by the crystal water content between the layered and spinel-like phases during the electrochemical reaction, could activate new cation sites, enhance ion diffusion kinetics and improve its structural stability. This work thus provides in-depth insights into the intercalating materials capable of reversible framework changes, thereby setting the precedent for alternative approaches to the development of cathode materials for next-generation rechargeable batteries.

Phase-Selective Disordered Anatase/Ordered Rutile Interface System for Visible-Light-Driven, Metal-Free CO2 Reduction.

Visible-light-driven photocatalytic CO2 reduction using TiO2 that can absorb light of all wavelengths has been sought for over half a century. Herein, we report a phase-selective disordered anatase/ordered rutile interface system for visible-light-driven, metal-free CO2 reduction using a narrow band structure, whose conduction band position matches well with the reduction potential of CO2 to CH4 and CO. A mixed disordered anatase/ordered rutile (Ad/Ro) TiO2 was prepared from anatase and rutile phase-mixed P25 TiO2 at room temperature and under an ambient atmosphere in sodium alkyl amine solutions. The Ad/Ro TiO2 showed a narrow band structure due to multi-internal energy band gaps of Ti3+ defect sites in the disordered anatase phase, leading to high visible light absorption and simultaneously providing fast charge separation through the crystalline rutile phase, which was faster than that of pristine P25 TiO2. The band gap of Ad/Ro TiO2 is 2.62 eV with a conduction band of -0.27 eV, which matches well with the reduction potential of -0.24 VNHE of CO2/CH4, leading to effective electron transfer to CO2. As a result, the Ad/Ro TiO2 provided the highest CH4 production (3.983 µmol/(g h)), which is higher than that of even metal (W, Ru, Ag, and Pt)-doped P25, for CO2 reduction under visible light.

Hierarchically Structured Core-Shell Design of a Lithium Transition-Metal Oxide Cathode Material for Excellent Electrochemical Performance.

Tuning geometrical parameters of lithium-mixed transition-metal oxide (LiTM) cathode materials is a promising strategy for resource-efficient design of high-performance Li-ion batteries. In this paper, we demonstrate that simple and facile geometrical tailoring of the secondary microstructure of LiTM cathode materials without complex chemical modification or heterostructure engineering can significantly improve overall electrochemical performance of the active cathode materials. An optimized LiTM with a bimodal size distribution of primary particles inside the secondary particles exhibits a 53.8% increase in capacity at a high discharge rate (10 C) compared to a commercially available reference and comparable rate capability after 100 charge/discharge cycles. The key concept of this approach is to maximize the beneficial effects arising from the controlled sizes of primary particles. Multimodal/multiscale microscopic characterizations based on electron tomography and scanning transmission electron microscopy, combined with electron energy-loss spectroscopy and energy-dispersive X-ray spectroscopy from the atomic level to the microscale level, were employed to elucidate structural origins of enhanced battery performance. This study paves the way for the resource-efficient microstructure design of LiTM cathode materials to maximize capacity and stability via simple adjustment of processing conditions, which is advantageous for mass-production applications.

Cerebral Aneurysms in Judicial Precedents.

OBJECTIVE: From November 30, 2016, the Korean Government carried the revised Medical Dispute Mediation and Arbitration Act into effect. Mediation will start automatically without agreements of the defendant, when the outcome of the patient was death, coma more than a month or severe disability. Cerebral aneurysm has a definite risk of bad outcome, especially in the worst condition. Any surgical intervention to this lesion has its own high risk of complications. Recently, Seoul central district court decided 50% responsibility of the doctors who made a rupture of the aneurysm during coiling (2015Ga-Dan5243104). We reviewed judicial precedents related to cerebral aneurysms in lawsuit using a web search. METHODS: We searched judicial precedents at a web search of the Supreme Court, using the key words, "cerebral aneurysm". RESULTS: There were 15 precedents, six from the Supreme Court, seven from the High Court, and two from district courts. Seven precedents were related to the causation analysis, such as work-relationship. Five precedents were malpractice suits related bad results or complications. Remaining three precedents were related to the insurance payment. In five malpractice precedents, two precedents of the Supreme Court reversed former two precedents of the High Court. CONCLUSION: Judicial precedents on the cerebral aneurysm included not only malpractice suits, but also causation analysis or insurance payment. Attention to these subjects is needed. We also need education of the independent medical examination. To avoid medical disputes, shared decision making seems to be useful, especially in cases of high risk condition or procedures.

Clinical Features of Interhemispheric Subdural Hematomas.

OBJECTIVE: Interhemispheric subdural hematoma (IHSDH) is uncommon, because of their unusual location. However, it is a distinct lesion with its unique characteristics. We investigated clinical features and outcomes of consecutive 42 patients with IHSDH, retrospectively. METHODS: From 2006 to 2015, we treated 105 patients with IHSDH. All patients were diagnosed by computed tomography (CT) or magnetic resonance imaging. We selected 42 patients with thick (3 mm or more) IHSDH. We retrospectively reviewed the clinical and radiological findings, management and outcomes. RESULTS: The male to female ratio was 2:1. Two thirds of the patients were over 60 years old. Slip or fall was the most common cause of trauma. The level of consciousness on admission was Glasgow Coma Scale (GCS) 13 to 15 in 25 patients. The most common symptom was headache. All IHSDH was hyperdense in CT at the time of diagnosis. IHSDH frequently accompanied convexity subdural hematoma. The outcome was favorable in 27 patients, however, six patients were expired. Twenty-two patients were managed conservatively. Surgery was performed in ten patients to remove the concurrent lesion. The outcome was poor in spontaneous one, patients with low GCS, and patients with conservative treatment. CONCLUSION: IHSDH is rare especially the isolated one. The outcome was dependent to the severity of injury. Surgery may be helpful to remove the concurrent mass lesion, however, conservative treatment is generally preferred.

Procedure-related Complications during Endovascular Treatment of Intracranial Saccular Aneurysms.

OBJECTIVE: We evaluate the rates and outcomes of major procedure-related complications during coiling. MATERIALS AND METHODS: Between 2007 and 2015, 436 intracranial saccular aneurysms were treated. Complications are categorized as three types: intraprocedural aneurysm rupture (IAR), thromboembolism (TE), and post-procedural early rebleeding (PER). And we evaluated the risk factors of procedure related complications by multivariate analysis. RESULTS: Complications occurred in 61 aneurysms (14%). The overall incidence of complications in subarachnoid hemorrhage (SAH) was significantly higher than in unruptured intracranial aneurysm (UIA) (20% vs. 6%). The incidence of IAR and TE were higher in SAH than in UIA (IAR 12% vs. 4%, TE 7% vs. 3%, p < 0.05). Five PER occurred only in SAH. In 34 UIA which were treated with balloon-assisted coiling (BAC), all these patients had good recovery despite 3 patients had the IAR. The incidence of IAR and TE were not different between BAC and non-BAC groups (p > 0.05). All 7 patients who had IAR during BAC had good recovery. In multiple logistic regression analysis, female gender, SAH, and intraventricular hemorrhage were associated with procedure related complication (p < 0.05). CONCLUSION: Endovascular coil embolization is a minimally invasive procedure, but incidence of its complication is not low, especially in SAH. BAC can be a good tool to avoid poor outcome from unexpected IAR during coiling. While IA tirofiban injection is a useful therapy in TE during coiling, sometimes we are aware of the risk of the early rebleeding in SAH patients.

Reduced Graphene Oxide-Wrapped Nickel-Rich Cathode Materials for Lithium Ion Batteries.

The encapsulation of Ni-rich cathode materials (LiNi0.6Co0.2Mn0.2O2) for lithium ion batteries in reduced graphene oxide (rGO) sheets is introduced to improve electrochemical performances. Using (3-aminopropyl)triethoxysilane, the active materials are completely wrapped with several rGO layers of ∼2 nm thickness. By virtue of the great electrical conductivity of graphene, the rGO-coated cathode materials exhibit much enhanced electrochemical performances of cycling property and rate capability. In addition, it is shown that the structural degradation of the active materials, which is from the rhombohedral layered structure (R3̅m) to the spinel (Fd3̅m) or rock-salt phase (Fm3̅m), is significantly reduced as well as delayed due to the protection of the active materials in the rGO layers from direct contact with electrolytes and the consequent suppression of side reactions.

Mixed Electronic and Ionic Conductor-Coated Cathode Material for High-Voltage Lithium Ion Battery.

A lithium ionic conductor, Li1.3Al0.3Ti1.7(PO4)3 (LATP), is introduced as a coating material on the surface of Mg-doped LiCoO2 to improve electrochemical performances for high-voltage (4.5 V) lithium ion batteries. Structure, morphology, elemental distribution, and electrical properties of the materials are thoroughly characterized by SEM, TEM, EELS, EDS, and C-AFM. The coating layer is electrically conductive with the aid of Mg ions which are used as a dopant for the active materials; therefore, this mixed electronic ionic conductor strongly enhances the electrochemical performances of initial capacity, cycling property, and rate capability. The LATP coating layer also demonstrates very promising applicability for 4.4 V prismatic full cells with graphite anode, which correspond to the 4.5 V half-cells with lithium anode. The 2900 mA h full cells show 85% of capacity retention after 500 cycles and more than 60% after 700 cycles.

Evaluation of engraftment of superparamagnetic iron oxide-labeled mesenchymal stem cells using three-dimensional reconstruction of magnetic resonance imaging in photothrombotic cerebral infarction models of rats.

OBJECTIVE: To evaluate engraftment by visualizing the location of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) three-dimensionally in photothrombotic cerebral infarction (PTCI) models of rats. MATERIALS AND METHODS: Magnetic resonance imaging (MRI) of an agarose block containing superparamagnetic iron oxide (SPIO)-labeled hBM-MSCs was performed using a 3.0-T MRI, T2-(T2WI), T2(*)-(T2(*)WI), and susceptibility-weighted images (SWI). PTCI was induced in 6 rats, and 2.5 × 10(5) SPIO-labeled hBM-MSCs were infused through the ipsilateral internal carotid artery (ICA group) or tail vein (IV group). MRI was performed on days 1, 3, 7, and 14 after stem cell injection. Dark signal regions were confirmed using histology. Three-dimensional MRI reconstruction was performed using the clinical workflow solution to evaluate the engraftment of hBM-MSCs. Volumetric analysis of the engraftment was also performed. RESULTS: The volumes of SPIO-labeled hBM-MSCs in the phantom MRI were 129.3, 68.4, and 25.9 µL using SWI, T2(*)WI, and T2WI, respectively. SPIO-labeled hBM-MSCs appeared on day 1 after injection, encircling the cerebral infarction from the ventral side. Dark signal regions matched iron positive cells and human origin (positive) cells. The volume of the engraftment was larger in the ICA group on days 1, 3, and 7, after stem cell injection (p < 0.05 on SWI). SWI was the most sensitive MRI pulse sequence (p < 0.05). The volume of infarction decreased until day 14. CONCLUSION: The engraftment of SPIO-labeled hBM-MSCs can be visualized and evaluated three-dimensionally in PTCI models of rats. The engraftment volume was larger in the ICA group than IV group on early stage within one week.

Chronic low back pain in young korean urban males: the life-time prevalence and its impact on health related quality of life.

OBJECTIVE: We assessed the life-time prevalence (LTP) of chronic low back pain (LBP) in young Korean males. We also evaluated the relationship between lumbar spinal lesions and their health related quality-of-life (HRQOL). METHODS: A cross-sectional, self-reported survey was conducted in Korean males (aged 19-year-old) who underwent physical examinations for the conscript. We examined 3331 examinees in November 2014. We included 2411 subjects, who accepted to participate this study without any comorbidities. We interviewed using simple binary questions for their LBP experience and chronicity. HRQOL was assessed by Short-Form Health-Survey-36 (SF-36) in chronic LBP and healthy control groups. Radiological assessment was performed in chronic LBP group to determine whether there were any pathological causes of their symptoms. RESULTS: The LTP of chronic LBP was 13.4%. Most (71.7%) of them didn't have any lumbar spinal lesions (i.e., non-specific chronic LBP). The SF-36 subscale and summary scores were significantly lower in subjects with chronic LBP. Between specific and non-specific chronic LBP group, all physical and mental subscale scores were significantly lower in specific chronic LBP group, except mental health (MH) subscale score. In MH subscale and mental component summary score, statistical significant differences didn't appear between two groups (p=0.154, 0.126). CONCLUSION: In Korean males 19 years of age, the LTP of chronic LBP was 13.4%, and more than two-thirds were non-specific chronic LBP. Chronic LBP had a significant impact on HRQOL. The presence of lumbar spinal pathoanatomical lesions affected mainly on the physical aspect of HRQOL. It influenced little on the mental health.

Usefulness of ultrasound for detecting suspected peripheral nerve lesions in diagnosis of peripheral neuropathy : case report and brief review of the literature.

Ultrasound scanning of a peripheral nerve along its expected course is a simple and useful method for determining the cause of peripheral neuropathy. We present 3 cases of peripheral neuropathy in which the pathology was detected by simple ultrasound scanning of the affected nerve. There were 2 cases of entrapment neuropathy due to mucoid cyst and 1 case of nerve sheath tumor. All lesions were visualized by simple ultrasound scanning of the involved peripheral nerve. Our results suggest that if a lesion affecting the peripheral nerve is suspected after history and physical examination or electrophysiologic studies, ultrasound scanning of the peripheral nerve of interest throughout its course is very helpful for identifying the causative lesion.

Which treatment modality is more injurious to the brain in patients with subarachnoid hemorrhage? Degree of brain damage assessed by serum S100 protein after aneurysm clipping or coiling.

BACKGROUND: Serum S100 protein has been known to reflect the severity of brain damage. The purpose of this study was to compare the degree of brain damage based on the serum S100 protein level between aneurysm clipping and coiling groups and to evaluate the prognostic value of S100 protein in patients with subarachnoid hemorrhage (SAH). METHODS: Serum S100 protein was measured by Elecsys S100 immunoassay at admission, and at 6 and 24 h, and days 3 and 5 postoperatively for 100 consecutive SAH patients (clipping group: 56, coiling group: 44) and for 74 healthy controls. Hunt-Hess grade (HHG), Fisher grade (FG), the presence of intraventricular (IVH) or intracerebral hemorrhage (ICH), and outcome at discharge were evaluated. The time course of serum S100 was compared between the groups. The prognostic value of S100 protein was evaluated by logistic regression analysis. RESULTS: The median S100 level in SAH patients on admission was significantly higher than in healthy controls (0.081 vs. 0.05 µg/l, p < 0.0001) and it was also higher as HHG and FG increased (p < 0.0001). Logistic regression analysis revealed that only the S100 value at admission was an independent prognostic factor for poor outcomes after adjusting for age, sex, HHG, presence of IVH or ICH, and treatment modality (OR: 100.5, 95% CI: 1.65-6,053.61). The baseline S100 value of 0.168 predicted poor outcomes with a sensitivity of 75% and a specificity of 83%. The time course of the median S100 level peaked at 6 h and then decreased serially in both clipping and coiling groups. However, the degree of S100 elevation was marked in the clipping group, especially at 6 h postoperatively (0.177 vs. 0.116 µg/l, p = 0.022), suggesting more severe brain damage in the clipping group. In the coiling group, the S100 value was significantly higher in patients who showed high signal intensity lesions in diffusion-weighted images, suggesting ischemic brain damage. Furthermore, even in patients who were categorized as good clinical grade at admission and as good outcome at discharge, the median S100 values at 6 and 24 h postoperatively were significantly higher in the clipping group than in the coiling group (p < 0.05). CONCLUSION: The initial S100 protein value is an independent prognostic factor for poor outcomes in SAH patients. Based on the S100 protein level, aneurysm clipping seems to provoke more brain damage than aneurysm coiling. Endovascular coiling should be considered the first therapeutic option for aneurysmal SAH patients.

Effect of the rutile content on the photovoltaic performance of the dye-sensitized solar cells composed of mixed-phase TiO2 photoelectrodes.

The effect of the rutile content on the photovoltaic performance of dye-sensitized solar cells (DSSCs) composed of mixed-phase TiO(2) photoelectrode has been investigated. The mixed-phase TiO(2) particles with varied amounts of rutile, relative to anatase phase, are synthesized by an in situ method where the concentration of sulfate ion is used as a phase-controlling parameter in the formation of TiO(2) using TiCl(4) hydrolysis. The surface area (S(BET)) varies from 33 (pure rutile) to 165 (pure anatase) m(2) g(-1). Generally, both the current density (J(sc)) and photo-conversion efficiency (η) decrease as the rutile content increases. The incorporation of rod-shaped rutile particles causes low uptake of dye due to the reduced surface area, as well as slow electron transport in less efficiently-stacked structure. However, maximum J(sc) (14.63 mA cm(-2)) and η (8.69%) appear when relatively low rutile content (16%) is employed. The reported synergistic effect by the efficient interparticle electron transport from rutile to anatase seems to overbalance the decrease of surface area when small amount of rutile particles is incorporated.

A case of intraosseous dural arteriovenous fistulas involving diploic vein treated with transarterial onyx embolization.

Intracranial dural arteriovenous fistulas (DAVFs) are abnormal arteriovenous connections that lie within the dura. Intraosseous DAVFs involving diploic venous system are extremely rare. A 46-year-old woman presented with headache and right pulsatile tinnitus for three weeks. The tinnitus started after yelling. Digital subtraction angiography revealed DAVF within the basal portion of right parietal bone along the middle meningeal artery (MMA) groove. The fistula was fed by frontal branch of right MMA and drained into right transverse sigmoid sinus junction through dilated middle meningeal vein. The intraosseous DAVF involving diploic vein was successfully obliterated with Onyx embolization via transarterial route.

Nanostructural, optical, and chemical features of Al-added nanocrystalline-Si thin films.

The nanostructural and optical features of Al-added nanocrystalline Si (nc-Si) thin films, which were prepared by co-sputtering Al-chips and a Si main target, were investigated in terms of Al-addition and post-deposition annealing conditions; the optical features like photoluminescence (PL) and electroluminescence (EL) were related with the variation in the nanostructure of the films. The PL intensity as well as the relative volume fraction of Si nanocrystallites increased with increasing the concentration of Al to a certain level. In particular, the PL spectra of the films which were prepared with 4 Al-chips and then annealed at 800 degrees C for 60 min exhibit a significant increase in intensity at a wavelength of approximately 620 nm, compared to those of the films prepared without Al-addition. It is highly likely that the observed increase in the PL intensity is caused by the raise in the total volume fraction of the approximately 3.0 nm-sized nanocrystallites in the films. It was found that the addition of Al as well as the post-deposition annealing can allow adjustment and control of the nanostructural and light-emission features of the nc-Si films.