Earticle

4-Dimethylaminocinnamaldehyde(이하 DMAC)는 요소에 반응하는 시약으로 알려져 있으며 요소는 에크린 분비선에서 물 다음으로 많은 양을 차지하고 있는 물질이다. 종이류의 잠재지문 현출에 있어서 아미노산에 반응하는 닌히드린과 그 계열의 형광반응 시약인 1,2-indanedione(이하 1,2-IND), 1,8-diazafluoren-9-one(이하 DFO) 등이 사용되었는데 이들은 반응하는 물질이 동일한 반면 형광세기와 환경은 각자 달라서 하나의 증거물에 아미노산 반응 시약들만을 순서적으로 적용하여 좋은 결과를 도출해 내는 것은 쉬운 일이 아니다. 이런 이유로 DMAC에 대한 연구를 통하여 아미노산 반응 형광시약들 보다 앞선 순서로 적용할 수 있는지 여부와 DMAC의 전처리가 이후 적용될 수 있는 아미노산 형광반응 시약들에 미치는 영향에 대해서 관찰하였고 그 결과 DMAC의 형광을 위한 ‘들뜸 스펙트럼-배리어 필터’ 간의 조합은 1,2-IND와 동일한 505nm-555nm라는 사실을 확인하였다. 따라서 1,2-IND 처리 이전에 적용할 경우에 1,2-IND 적용 결과로 얻어지는 지문의 대조비를 더 강하게 하는 효과가 있는 것으로 관찰되었다. 또한 DMAC를 단독으로 처리한 경우에도 DFO와 비슷한 수준의 형광지문 대조비를 보인다는 사실을 확인하였다. DMAC는 증거물 표면을 강하게 염색하는 특징을 갖고 있어서 담금법을 적용하기 어려웠지만 그 농도를 0.003%까지 낮출 경우 기존에 제시된 고농도의 무용매 접촉법을 적용할 때 보다 더 강한 대조비의 형광 지문을 확보할 수 있으면서도 검체에는 손상을 주지 않는 것을 확인하였다. 결과적으로 종이류 잠재지문 현출 기법으로 DMAC를 가장 우선적으로 적용하는 것은 이후 아미노산 반응 시약을 적용함에 있어서 아무런 부작용을 주지 않기 때문에 전처리 기법 또는 단독 처리 기법으로 권장할 수 있다.

DMAC is believed to react with the urea present in eccrine fingerprint secretions. In this study, the best result of the fingerprint developed by DMAC is observed when the excitation is 505nm band and the barrier filter band is 555nm. This light and filter condition is same in the use of 1,2-IND reagent. If DMAC is used as pre-treatment of 1,2 IND, the fluorescent print reacts more strongly. this enhancement is produced by the same light and barrier filter condition of two reagents. when DMAC is used as pre-treatment of DFO, this enhancement is not revealed. In addition, the contact transfer technique of DMAC is recommended as the method that can use on the thermal paper.

Cellulose filaments were produced from cellulose solution of 9% LiCl/DMAc solvent using a laboratory scale wet spinning machine. The tenacities of spun cellulose fibers were increased with increasing cellulose concentration of spinning solution, draw ratio and LiCl concentration in coagulation bath, and they were decreased with increasing bath temperature. The crystalline structure of spun cellulose fiber was similar to that of viscose rayon and its crystallinity and orientation were increased with increasing draw ratio.

Because of the demands for high performance and high integrated system, the needs for optimal platform becomes more importance. Optimal platform can handle more data effectively with same resources. AMBA(Advanced Microprocessor Bus Architecture)$^{TM}$ defines on-chip communication standard for designing high performance embedded micro-controllers. It is consisted of AHB, ASB and APB. It can support fast implementation and reliability in system that is composed with reusable IPs. DMAC is one of master in system and generate master signals of AHB to communicate data from one slave(peripheral or memory) to another slave. It can reduce burden of CPU and increase system performance. We designed DMAC based on AMBA and it supports 13 Channels. Each channel can be controlled by software program. It decides channel's priority using round-robin method. It can support P2P, P2M, M2P and P2P communication.

The solutions of polyvinylidene fluoride (PVDF) in dimethyl acetamide (DMAc) were rheologically investigated. In the dilute concentration regime, the solutions gave values of Huggins constant lower than 0.52, which decreased with increasing temperature. This suggests that DMAc is a good solvent and the solvating power is increased with increasing temperature. The solutions exhibited an inflection point on the log-log plot of $\eta_{sp}$ versus $(\eta)C$. Further, the slope was slightly decreased with increasing temperature from 10 to $30^{\circ}C$. At high concentrations, the solutions did not show lower Newtonian flow region. Further, raising temperature from 10 to $30^{\circ}C$ increased viscosity and yield stress of the solutions. Increasing concentration had the same effect on the rheological properties as increasing temperature. Relaxation time $(\lambda) $ increased as the concentration and temperature increased.

Ad hoc MAC protocols using directional antennas can be used to improve the network capacity by improving spatial reuse. But, the directional MAC protocols have the problem of deafness and have a poor throughput performance. The dual-channel DMAC protocol has been proposed to mitigate deafness and improve spatial reuse. In this paper, we propose a dual-channel DMAC protocol using the omnidirectional antenna for an out-of-band tone and directional antennas for control/data channels. In the proposed MAC protocol, an omnidirectional out-of-band tone mitigates deafness and directional antennas used in control/data channels improve spatial reuse and reduce interference packets. The throughput performance of the proposed MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.

Directional antennas are used to improve spatial reuse, but have the problem of deafness. The DUDMAC protocol uses the ORTS, OCTS, DDATA, and DACK mechanisms and a blocking algorithm for directional transmissions. In this paper, we propose a tone dual-channel directional MAC (Tone DUDMAC) protocol to improve spatial reuse. The Tone DUDMAC protocol uses the ORTS, DCTS, DDATA, and DACK mechanisms including the DDATA_tone and OCTS_tone. We use ORTS as that in DUDMAC because of location unawareness of neighbor's nodes. The DDATA_tone and OCTS_tone reduce a blocking area and improve spatial reuse. We confirm the throughput performance of the proposed MAC protocol by computer simulations using Qualnet ver.3.8 simulator.

In this paper, we describe implemented DMAC (Direct Memory Access Controller) architecture on Altera's $Excalibur^{TM}$ that includes industry-standard $ARM922T^{TM}$ 32-bit RISC processor core operating at 200 MHz. We implemented DMAC based on AMBA (Advanced Micro-controller Bus Architecture) AHB (Advanced Micro-performance Bus) interface. Implemented DMAC has 8-channel and can extend supportable channel count according to user application. We used round-robin method for priority selection. Implemented DMAC supports data transfer between Memory-to-Memory, Memory-to-Peripheral and Peripheral-to-Memory. The max transfer count is 1024 per a time and it can support byte, half-word and word transfer according to AHB protocol (HSIZE signals). We implemented with VHDL and functional verification using $ModelSim^{TM}$. Then, we synthesized using $LeonardoSpectrum^{TM}$ with Altera $Excalibur^{TM}$ library. We did FPGA P&R and targeting using $Quartus^{TM}$. We can use implemented DMAC module at any system that needs high speed and broad bandwidth data transfers.

공정의 안전을 위해서 취급물질의 정확한 연소특성치의 사용은 매우 중요하다. 화학산업에서 다양하게 사용되고 있는 디메틸아세트아미드의 안전한 취급을 위해서 인화점과 최소자연발화온도를 측정하였다. 폭발하한계는 실험에서 얻어진 하부인화점을 이용하여 계산하였다, Setaflash 밀폐식은 $61^{\circ}C$, Pensky-Martens 밀폐식에서는 $65^{\circ}C$ 그리고 Tag 개방식에서는 $68^{\circ}C$, Cleveland 자동 개방식에서는 $71^{\circ}C$로 측정되었다. ASTM E659 장치에 의한 최소자연발화온도는 $347^{\circ}C$로 측정되었다. 측정된 하부인화점 $61^{\circ}C$에 의한 폭발하한계는 1.52 vol%로 계산되었다. 폭발한계는 측정된 인화점이나 문헌에 제시된 인화점을 이용하여 예측가능함을 알 수 있었다.

The usage of the correct combustion characteristic of the treated substance for the safety of the process is critical. For the safe handling of dimethylacetamide (DMAc) being used in various ways in the chemical industry, the flash point and the autoignition temperature (AIT) of DMAc was experimented. And, the lower explosion limit of DMAc was calculated by using the lower flash point obtained in the experiment. The flash points of DMAc by using the Setaflash and Pensky-Martens closed-cup testers measured $61^{\circ}C$ and $65^{\circ}C$, respectively. The flash points of DMAc by using the Tag and Cleveland automatic open cup testers are measured $68^{\circ}C$ and $71^{\circ}C$. The AIT of DMAc by ASTM 659E tester was measured as $347^{\circ}C$. The lower explosion limit by the measured flash point $61^{\circ}C$ was calculated as 1.52 vol%. It was possible to predict lower explosion limit by using the experimental flash point or flash point in the literature.

Mixed-valence MnO/Mn₃O₄/carbon (MnO/Mn₃O₄/C) composites were synthesized via a one-step solvothermal process followed by thermal annealing, utilizing N,N-dimethylacetamide (DMAc) as a dual-function solvent and insitu carbon source. By precisely tuning the annealing temperature, the structural and electrochemical properties of the resulting composites were optimized. Notably, the sample annealed at 500℃ (Mn-N5) exhibited a balanced Mn²⁺/Mn³⁺ ratio, abundant oxygen vacancies, and a conductive sp² -rich carbon framework. These features collectively enhanced lithium-ion diffusion, electron transport, and mechanical integrity. As an anode material, Mn-N5 delivered a high reversible capacity of 861?mAh?g^-1 at 0.2?A?g^-1 , retained 309?mAh?g^-1 at 2?A?g^-1 , and maintained 473?mAh?g^-1 after 1000 cycles at 0.5?A?g^-1 . Kinetic analysis and impedance spectroscopy confirmed improved charge transfer and pseudocapacitive behavior, driven by the synergistic effects of the heterostructured MnO_x and carbon network. These results demonstrate a scalable and cost-effective strategy for engineering high-performance Mn-based anodes suitable for next-generation lithium-ion batteries.