Full-duplex wireless light communication using green laser diodes.

The integration of wireless light communication into a wireless fidelity (Wi-Fi) module and gateway enables real-time integrated communication networks that satisfy practical application demands. In particular, wireless green light communication tools can operate underwater and in free-space environments. Here, we design, fabricate, and characterize a full-duplex light communication system using green laser diodes (LDs). Operating within the transmission control protocol/internet protocol (TCP/IP), full-duplex wireless data transmission is confirmed in underwater and free-space environments at a communication rate of 10 Mbps. Through connections to a Wi-Fi module and gateway, the system is accessed by the network via the TCP/IPv4 internet scheme, and real-time video transmission is demonstrated.

All-light communication network for space-air-sea integrated interconnection.

Space-air-sea communication networks are of great interest to meet the demand for close and seamless connections between space, land, and ocean environments. Wireless light communication can expand network coverage from land to the sky and even the ocean while offering enhanced anti-interference capabilities. Here, we propose and establish an all-light communication network (ALCN) for space-air-sea integrated interconnection, which merges underwater blue light communication, wireless white light communication, solar-blind deep ultraviolet light communication and laser diode-based space communication. Ethernet switches and the Transmission Control Protocol are used for space-air-sea light interconnection. Experimental results show that the ALCN supports wired and wireless device access simultaneously. Bidirectional data transmission between network nodes is demonstrated, with a maximum packet loss ratio of 5.80% and a transmission delay below 74 ms. The proposed ALCN provides a promising scheme for future space-air-sea interconnections towards multiterminal, multiservice applications.

Ultrasonic aerosol agglomeration: Manipulation of particle deposition and its impact on air filter pressure drop.

Acoustic agglomeration is a technique that leverages on sound waves to promote the collision of aerosol particulate matter, thus leading to the formation of larger particle agglomerates. In this study, this acoustics-driven phenomenon is demonstrated for its usefulness as an aerosol pre-conditioning method to significantly enhance the efficiency of filtration systems in particle treatment processes. Specifically, favorable changes in pressure drop across the filters are observed as a result of receiving less particle mass, for which filters are shown to be able to have their operational life extended remarkably by more than 50%. The involved ultrasonic aerosol agglomeration mechanisms are unveiled through numerical simulations, and the effects of residence time, sound pressure level, and initial particle number concentration on agglomeration performances are experimentally investigated. In addition, validations and measurements of filter pressure drop are obtained through a series of experiments. This study provides a comprehensive overview to the design and performance characterization of acoustics-agglomeration-enhanced filtration systems, which could potentially derive energy savings for fan power in ventilation systems and be scaled up for applications in industrial plants for reducing carbon emissions.

Acoustofluidic Interfaces for the Mechanobiological Secretome of MSCs.

While mesenchymal stem cells (MSCs) have gained enormous attention due to their unique properties of self-renewal, colony formation, and differentiation potential, the MSC secretome has become attractive due to its roles in immunomodulation, anti-inflammatory activity, angiogenesis, and anti-apoptosis. However, the precise stimulation and efficient production of the MSC secretome for therapeutic applications are challenging problems to solve. Here, we report on Acoustofluidic Interfaces for the Mechanobiological Secretome of MSCs: AIMS. We create an acoustofluidic mechanobiological environment to form reproducible three-dimensional MSC aggregates, which produce the MSC secretome with high efficiency. We confirm the increased MSC secretome is due to improved cell-cell interactions using AIMS: the key mediator N-cadherin was up-regulated while functional blocking of N-cadherin resulted in no enhancement of the secretome. After being primed by IFN-γ, the secretome profile of the MSC aggregates contains more anti-inflammatory cytokines and can be used to inhibit the pro-inflammatory response of M1 phenotype macrophages, suppress T cell activation, and support B cell functions. As such, the MSC secretome can be modified for personalized secretome-based therapies. AIMS acts as a powerful tool for improving the MSC secretome and precisely tuning the secretory profile to develop new treatments in translational medicine.

Touchless Input/Output Interface for Device-to-Device Communication.

Multiple quantum well (MQW) III-nitride diodes show selectable functionalities of light-emitting and light-detecting behaviors, enabling direct touchless device-to-device communication. Here, we propose and demonstrate a touchless input/output (I/O) interface using a single MQW III-nitride diode. By integrating an MQW III-nitride diode with a memory via a control circuit, optical signals are converted into electrical ones to be written into a memory, and consequently, electrical information is read out from the memory to be translated into optical signals for visible light communication (VLC). The MQW III-nitride diode can not only lead to a touchless ″writing″ action but also offer a ″reading″ process through light. Such touchless I/O interface would provide new forms of interactivity for device-to-device communication technologies.

Artificial-Neural-Network-Driven Innovations in Time-Varying Process Diagnosis of Low-K Oxide Deposition.

To address the challenges in real-time process diagnosis within the semiconductor manufacturing industry, this paper presents a novel machine learning approach for analyzing the time-varying 10th harmonics during the deposition of low-k oxide (SiOF) on a 600 Å undoped silicate glass thin liner using a high-density plasma chemical vapor deposition system. The 10th harmonics, which are high-frequency components 10 times the fundamental frequency, are generated in the plasma sheath because of their nonlinear nature. An artificial neural network with a three-hidden-layer architecture was applied and optimized using k-fold cross-validation to analyze the harmonics generated in the plasma sheath during the deposition process. The model exhibited a binary cross-entropy loss of 0.1277 and achieved an accuracy of 0.9461. This approach enables the accurate prediction of process performance, resulting in significant cost reduction and enhancement of semiconductor manufacturing processes. This model has the potential to improve defect control and yield, thereby benefiting the semiconductor industry. Despite the limitations imposed by the limited dataset, the model demonstrated promising results, and further performance improvements are anticipated with the inclusion of additional data in future studies.

Diagnosing Time-Varying Harmonics in Low-k Oxide Thin Film (SiOF) Deposition by Using HDP CVD.

This study identified time-varying harmonic characteristics in a high-density plasma (HDP) chemical vapor deposition (CVD) chamber by depositing low-k oxide (SiOF). The characteristics of harmonics are caused by the nonlinear Lorentz force and the nonlinear nature of the sheath. In this study, a noninvasive directional coupler was used to collect harmonic power in the forward and reverse directions, which were low frequency (LF) and high bias radio frequency (RF). The intensity of the 2nd and 3rd harmonics responded to the LF power, pressure, and gas flow rate introduced for plasma generation. Meanwhile, the intensity of the 6th harmonic responded to the oxygen fraction in the transition step. The intensity of the 7th (forward) and 10th (in reverse) harmonic of the bias RF power depended on the underlying layers (silicon rich oxide (SRO) and undoped silicate glass (USG)) and the deposition of the SiOF layer. In particular, the 10th (reverse) harmonic of the bias RF power was identified using electrodynamics in a double capacitor model of the plasma sheath and the deposited dielectric material. The plasma-induced electronic charging effect on the deposited film resulted in the time-varying characteristic of the 10th harmonic (in reverse) of the bias RF power. The wafer-to-wafer consistency and stability of the time-varying characteristic were investigated. The findings of this study can be applied to in situ diagnosis of SiOF thin film deposition and optimization of the deposition process.

Unification of Irreversibility and Energy Diagram Theory.

A simultaneous emission-detection phenomenon occurs when a quantum well (QW) diode is biased with a forward voltage and illuminated with a shorter-wavelength light beam. The diode is able to detect and modulate light emitted by itself due to its spectral emission-detection overlap. Here, two identical QW diode units separately function as a transmitter and a receiver to establish a wireless light communication system. In association with energy diagram theory, we explain the irreversibility between light emission and light excitation in the QW diode, which may help us deeply understand various expressions in nature.

Multilevel Simultaneous Lighting-Imaging System.

In a III-nitride multiple quantum well (MQW) diode biased with a forward voltage, electrons recombine with holes inside the MQW region to emit light; meanwhile, the MQW diode utilizes the photoelectric effect to sense light when higher-energy photons hit the device to displace electrons in the diode. Both the injected electrons and the liberated electrons are gathered inside the diode, thereby giving rise to a simultaneous emission-detection phenomenon. The 4 × 4 MQW diodes could translate optical signals into electrical ones for image construction in the wavelength range from 320 to 440 nm. This technology will change the role of MQW diode-based displays since it can simultaneously transmit and receive optical signals, which is of crucial importance to the accelerating trend of multifunctional, intelligent displays using MQW diode technology.

Full-duplex underwater wireless blue light communication.

Owing to its relatively low absorption loss and high data transmission rate, wireless blue light communication is becoming an increasingly attractive technology for underwater applications. Here, we demonstrate an underwater optical wireless communication (UOWC) system that communicates using blue light-emitting diodes (LEDs) with a dominant wavelength of 455 nm. Under the on-off keying modulation scheme, the waterproof UOWC system achieves a bidirectional communication rate of 4 Mbps based on the transmission control protocol (TCP) and exhibits real-time full-duplex video communication with a transmission distance of 12 m in a swimming pool, offering great potential for practical use in real-world scenarios, such as carried around or attached to an autonomous vehicle.

Study on the Preparation and Performance of Silicone-Modified Phenolic Resin Binder for Rail Grinding Wheels.

A scheme for manufacturing heavy-duty rail grinding wheels with silicone-modified phenolic resin (SMPR) as a binder in the field of rail grinding is presented to improve the performance of grinding wheels. To optimize the heat resistance and mechanical performance of rail grinding wheels, an SMPR for industrial production of rail grinding wheels was prepared in a two-step reaction using methyl-trimethoxy-silane (MTMS) as the organosilicon modifier by guiding the occurrence of the transesterification and addition polymerization reactions. The effect of MTMS concentration on the performance of silicone-modified phenolic resin for application in rail grinding wheels was investigated. The molecular structure, thermal stability, bending strength, and impact strength values of the SMPR were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and mechanical property testing, and the effect of MTMS content on the resin properties was investigated. The results indicated that MTMS successfully improved the performance of the phenolic resin. The thermogravimetric weight loss temperature of the SMPR modified by MTMS with 40% phenol mass at 30% weight loss is 66% higher than that of common phenolic resin (UMPR), exhibiting the best thermal stability; in addition, its bending strength and impact strength were enhanced by approximately 14% and 6%, respectively, compared with those of common UMPR. This study utilized an innovative Bronsted acid as a catalyst and simplified several intermediate reactions in the conventional silicone-modified phenolic resin technology. This new investigation of the synthesis process decreases the manufacturing cost of the SMPR, liberates it from the restrictions of grinding applications, and enables the SMPR to maximize its performance in the rail grinding industry. This study serves as a reference for future work on resin binders for grinding wheels and the development of rail grinding wheel manufacturing technology.

Compact Fluorescence Detection System Based on a Monolithic DBR-Integrated III-Nitride LED Chip.

Portable applications of fluorescence detection systems have gained much attention in various fields and require system components to be small and compact. In this work, we report on a compact fluorescence detection system and demonstrate its application for fluorescence sensing and imaging. The light source and filter are integrated on a single chip for the proposed system, which not only realizes the separation between excitation and fluorescent lights but also improves the light-emitting diode (LED) light extraction efficiency. Furthermore, the detection system allows for a removable sample unit. The results indicate that the performance of the distributed Bragg reflector (DBR) filter based on an amorphous dielectric film is excellent with selection ratios larger than 4600:1. The peak emission wavelength of the LED is 528 nm. The influence of green light leakage can be neglected, and the fluorescent red light is dominant when the fluorescence detection system is used for sensing and imaging. The low-cost and monolithic DBR-integrated III-nitride LED chip makes the proposed architecture a competitive candidate for portable fluorescence detection applications.

Reduction in Five Harmful Substances in Fried Potato Chips by Pre-Soaking Treatment with Different Tea Extracts.

Thermally processed food always contains various types of harmful substances. Control of their levels in food is important for human health. This work used the extracts from green tea dust, old green tea, yellow tea, white tea, oolong tea, and black tea to simultaneously mitigate diverse harmful substances in fried potato chips. The six tea extracts (30 g/L) all showed considerable inhibitory effects on the formation of 5-hydroxymethylfurfural (reduced by 19.8%-53.2%), glyoxal (26.9%-36.6%), and methylglyoxal (16.1%-75.1%). Green tea and black tea extracts exhibited better inhibitory abilities than the other three teas and were further investigated for other harmful compounds by various concentration treatments. Finally, pre-soaking of fresh potato slices in 50 g/L extracts of green tea dust displayed, overall, the most promising inhibitory capacity of HMF (decreased by 73.3%), glyoxal (20.3%), methylglyoxal (69.7%), acrylamide (21.8%), and fluorescent AGEs (42.9%) in fried potato chips, while it exhibited the least impact on the color and texture. The high level of catechins in green tea dust may contribute most to its outstanding inhibitory effect, whereas the distinguished inhibitory effect of black tea extract was speculated to be attributable to the high levels of theaflavins and amino acids in the fully fermented tea. This study indicated that green tea dust, a predominant waste of the tea industry, had great potential to be exploited to improve food quality and safety.

Investigating the Effect of Grinding Time on High-Speed Grinding of Rails by a Passive Grinding Test Machine.

High-speed rail grinding is a unique passive grinding maintenance strategy that differs from conventional grinding techniques. Its grinding behavior is dependent on the relative motion between the grinding wheel and rail; hence, it possesses great speed and efficiency. In this study, the effects of the duration of grinding time and the increase in the number of grinding passes on the grinding of high-speed rails were investigated using passive grinding tests with a single grinding time of 10 s and 30 s and grinding passes of once, twice, and three times, respectively. The results show that when the total grinding time was the same, the rail removal, grinding ratio of grinding wheels, rail grinding effect, grinding force, and grinding temperature were better in three passes of 10 s grinding than in one pass of 30 s grinding, indicating that the short-time and multi-pass grinding scheme is not only conducive to improving the grinding efficiency and grinding quality in the high-speed rail grinding but can also extend the service life of the grinding wheels. Moreover, when the single grinding times were 10 s and 30 s, respectively, the grinding removal, grinding efficiency, grinding marks depth, and surface roughness of rail increased with the number of grinding passes, implying that the desired rail grinding objective can be achieved by extending the grinding time via the multi-pass grinding strategy. The results and theoretical analysis of this study will contribute to re-conceptualizing the practical operation of high-speed rail grinding and provide references for the development of the grinding process and grinding technology.

Full-duplex wireless deep ultraviolet light communication.

With recent advancements in deep ultraviolet (DUV) light-emitting diodes (LEDs) and solar-blind photodetectors, wireless DUV light communication is emerging as a novel technique, which can extend transmission ranges and avoid solar interference. Herein, a full-duplex, real-time wireless light communication system using 275 nm DUV LEDs is proposed. We adopted high-power DUV LEDs and designed a high-speed transmitter, a high-sensitivity receiver, and a main processing unit for the system. Furthermore, the DUV communication system, using a Reed-Solomon (RS) encoder and an on-off keying (OOK) modem with frequency control, achieves a 10 Mbit/s bidirectional data transmission rate within 5 m in free space, while a full-duplex video communication link is formed. The encapsulated DUV communication system described in this Letter provides a feasible scheme for confidential and anti-electromagnetic interference communication in Internet of Things (IoT) applications.

Enabling a high-performance saltwater Al-air battery via ultrasonically driven electrolyte flow.

As an emerging battery technology, the Al-air flow battery (AAFB) exhibits high energy density due to the recycling of electrolytes, thus showing great potential as a type of clean and sustainable energy storage system. Conventionally, it employs an external mechanical pump to recycle the electrolyte. In this work, the saltwater AAFB in which the electrolyte is recycled by the ultrasonic capillary effect (rather than a mechanical pump) and the reaction chamber is agitated by ultrasonic vibration, is proposed and investigated. Our numerical simulations show that a travelling ultrasonic wave in the electrolyte flow system causes the capillary flow and agitation. The experimental results show that the percentage increase of the peak power density (relative to that with static electrolyte) can be up to about 7.5 times of that with the electrolyte flow driven by a mechanical pump, under the same electrolyte flow rate and concentration (3.3 ml min-1 and 3 M NaCl). The optimal peak power density, which can be achieved by optimizing the reaction chamber thickness, electrolyte concentration and ultrasonic vibration velocity, is 43.88 mW cm-2. This work illustrates that the acoustofluidic method can not only improve the discharge performance of the saltwater AAFB effectively, but also greatly decrease the energy consumption, weight and volume of the electrolyte driving unit of the AAFB. In addition, analyses based on experimental results show that the energy gain of a series/parallel battery system formed by multiple identical cells can be larger than one, if the number of cells in the system is large enough.

Formation and metabolism of 6-(1-acetol)-8-(1-acetol)-rutin in foods and in vivo, and their cytotoxicity.

Methylglyoxal (MGO) is a highly reactive precursor which forms advanced glycation end-products (AGEs) in vivo, which lead to metabolic syndrome and chronic diseases. It is also a precursor of various carcinogens, including acrylamide and methylimidazole, in thermally processed foods. Rutin could efficiently scavenge MGO by the formation of various adducts. However, the metabolism and safety concerns of the derived adducts were paid less attention to. In this study, the optical isomers of di-MGO adducts of rutin, namely 6-(1-acetol)-8-(1-acetol)-rutin, were identified in foods and in vivo. After oral administration of rutin (100 mg/kg BW), these compounds reached the maximum level of 15.80 µg/L in plasma at 15 min, and decreased sharply under the quantitative level in 30 min. They were detected only in trace levels in kidney and fecal samples, while their corresponding oxidized adducts with dione structures presented as the predominant adducts in kidney, heart, and brain tissues, as well as in urine and feces. These results indicated that the unoxidized rutin-MGO adducts formed immediately after rutin ingestion might easily underwent oxidation, and finally deposited in tissues and excreted from the body in the oxidized forms. The formation of 6-(1-acetol)-8-(1-acetol)-rutin significantly mitigated the cytotoxicity of MGO against human gastric epithelial (GES-1), human colon carcinoma (Caco-2), and human umbilical vein endothelial (HUVEC) cells, which indicated that rutin has the potential to be applied as a safe and effective MGO scavenger and detoxifier, and AGEs inhibitor.

Effective integration of a MOSFET phototransistor to a GaN LED for UV sensing.

In this Letter, we report an effective monolithic integration of a metal oxide semiconductor field effect (MOSFET) phototransistor (PT) and a light-emitting diode (LED) on a GaN-on-Si LED epitaxial (epi) wafer. Avoiding additional growth or Si diffusion, the PT was directly fabricated on the LED epi layer, providing a cost-effective and facile method. As a driver, the PT could modulate both peak value of the light intensity and output current of the integrated LED. As an ultraviolet (UV) detector, our PT showed sufficient responsivity. It was found that the gate-voltage-dependent photocurrent-response of the device had a shorter response time, and a higher responsivity was obtained at a higher gate-voltage bias. The device demonstrated a switching effect that the photoinduced current from the PT drove the LED when the UV lamp was turned on, whereas the photoinduced current stopped driving upon powering off the UV lamp. The experiment proved that the integrated device working as a UV detector exhibited a fast response time and a longstanding stability. We anticipate that such an approach could have potential applications for UV light detection and visible light communication (VLC).

Experimental Demonstration and Theoretical Analysis of Simultaneous Emission-Detection Phenomenon.

The demand for on-chip multifunctional optoelectronic systems is increasing in the Internet-of-Things era. Spectral emission-detection overlap endows an InGaN/GaN quantum well diode (QWD) with an intriguing capability to detect and modulate light emitted by itself, which is of great interest when merging electronics and photonics together on a single chip for the development of advanced information systems. When biased and illuminated at approximately the same time, the InGaN/GaN QWD can achieve light emission and detection simultaneously. Herein, we experimentally demonstrate the simultaneous emission-detection phenomenon and analyze the irreversibility of spectral emission-detection overlap according to energy diagram theory, which may answer why the QWD can only detect and modulate higher-energy photons than those emitted by itself.

A Comparative Study of Milk Fat Extracted from the Milk of Different Goat Breeds in China: Fatty Acids, Triacylglycerols and Thermal and Spectroscopic Characterization.

Goat milk (GM) is an excellent alternative to cow milk and has recently been used in commercial infant formula preparation due to its superior fat composition. Here, the fatty acid (FA) composition, triacylglycerol (TAG) molecular species, thermal behavior and infrared spectra of extracted milk fat from the milk of the two main breeds of dairy goat bred in China (Guanzhong GM (GZG) and Xinong Saanen GM (XSG)) are investigated. Gas chromatography, Fourier-transform infrared spectroscopy, differential scanning calorimetry and ultra-performance convergence chromatography with quadrupole time-of-flight mass spectrometry are applied. The obtained results evidence significant fat compositional differences based on the breed that produced the considered GM. The major FAs in both GM fats were capric (C10:0), myristic (C14:0), palmitic (C16:0), stearic (C18:0) and oleic (C18:1 n-9c). GZG presented a higher content of medium-chain saturated FAs, while XSG had higher unsaturated FAs with higher ratios of L/Ln and n-6/n-3. A total of 339 and 359 TAGs were detected and quantified in GZG and XSG, and the major TAGs were those of m/z 740.6712 (14.10 ± 0.27%) and m/z 684.6094 (10.94 ± 0.02%), respectively. Milk TAGs of GZG and XSG showed 24-54 and 26-54 total acyl carbon numbers with a 0-4 and 0-5 double bond number at 68 and 72 various retention times, respectively. Thermal analysis showed that all GM fat samples melted below normal body temperature. Infrared spectra revealed higher absorption values of GZG milk fat. This study provides valuable information to the dairy industry sector about GM fat produced in China, assessing the appropriateness of Chinese GM fat to be applied in Chinese infant formula.