Itochu (Japan)

To evaluate parameters measured using the tear film imager (TFI) prototype, a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers. In this cross-sectional study, patients with dry eye, meibomian gland dysfunction (MGD), and non-dry eye/MGD from February 2020 to January 2021 were analyzed. Quantified TFI outputs included lipid layer thickness (LLT), mucoaqueous layer thickness (MALT), MALT rate of change (MALTR), and lipid breakup time. Two other interferometry devices, LipiView2 and DR-1α, were used for comparison. TFI outputs and other clinical parameters were analyzed using correlation coefficients. Each patient underwent one or several study visits. Baseline values of three device outputs, other clinical parameters, and their changes were examined. This study involved 28 patients (8 patients with dry eyes, 13 with MGD, and 7 with non-dry eye/MGD). Baseline TFI, LipiView2, and DR-1α values were associated with various clinical parameters. The LLT values estimated using TFI had a correlation with the plugging score in the upper eyelid (r=-0.42). Several TFI values have correlated better than LipiView2 and DR-1α, particularly with questionnaire scores. MALTR by TFI revealed a correlation between standardized patient evaluation on eye dryness (SPEED) and dry eye-related quality of life score (DEQS) scores (r=0.59, 0.43), respectively. TFI enabled to quantify the LLT and MALT separately over time and shows the moderate correlations between TFI measurements and clinical parameters, which yields the potential for TFI to serve as a complementary tool for assessing dry eye and MGD.

To measure autonomic nerve activity (ANA) in several eye conditions and verify whether ANA modulation is regulated by peripheral or central control in short tear film break-up time dry eye (sBUTDE). This study included 23 eyes of 23 patients with sBUTDE (mean age 55.2 ± 16.1years; range 21-88years) and 24 eyes of 24 age-matched non-dry eye (DE) controls. An ANA measurement, personality questionnaire, and Ocular Surface Disease Index were administered. ANA was continuously measured for 10 minutes under three conditions: eyes closed, eyes open, and eyes open under ocular surface anesthesia. The low-frequency (LF)/high-frequency (HF) ratio (LF/HF) with eyes closed was significantly higher in the sBUTDE group than in the control group (P < 0.05). In the sBUTDE group, HF increased and LF/HF decreased with eye opening compared with those in the control group; HF with eyes open decreased with ocular surface anesthesia and reached the same level as that in the control group. Among patients where HF decreased or LF/HF increased with eye opening, 57.1% or 64.3% showed a tendency to return to the ANA state with eyes closed by ocular surface anesthesia, respectively. Factors associated with DE symptoms included break-up time, HF with eyes open, and "openness" (P < 0.05). ANA modulation can be caused by peripheral, central, or mixed abnormalities in sBUTDE. Furthermore, personality traits may play a role in symptom induction. Understanding the pathogenesis of sBUTDE may aid in the treatment of cases that are refractory to conventional treatments.

The microstructural changes and crack propagation in the carburized layer of SUS304 stainless steel due to repeated vacuum carburizing quenching as a heat treatment basket were investigated in this paper. As a result, beneath a graphite scale formed on the outermost surface, it was revealed that there were three types of carburized layers with different morphologies: M7C3 layer, M7C3/M23C6 mixed layer, and M23C6 layer (M = Cr, Mn, Fe). In addition, the surface was found to be uneven due to the occurrence of metal dusting. Besides, repeated heating and quenching caused the formation of voids in carbides and matrix in the carburized layer, and micro cracks appeared in the surrounding areas. Under the loading stress during vacuum carburizing quenching, these voids, micro cracks, and the uneven surface are considered to be the initial points for cracking.

Bu makale, İslam ahlakının ekonomik sistem üzerindeki kurucu rolünü ele almaktadır. Çalışma, İslam’da ahlak ve ekonominin ilişkisini tarihsel ve çağdaş bağlamlarda inceleyerek İslam ekonomisinin temellerini ve bileşenlerini değerlendirmektedir. İslam’da ve özellikle Kur’an’da ahlak ve ekonominin hangi kavramlar bağlamında ele alındığı incelendikten sonra, İslam ekonomisi literatüründe yer alan farklı sosyo-ekonomik modeller ve örnekler üzerinden bir tartışma yürütülmektedir. Ekonomiyle ahlak arasındaki güçlü ilişkiyi vurgulayan İslam ahlak ekonomisi kavramsallaştırması öne çıkarılmaktadır. İslam ahlak ekonomisinin kuramsal temelleri dört ana aksiyom çerçevesinde ele alınmaktadır: tevhid, denge, özgür irade ve sorumluluk. Kur’an’daki birr ayeti ve İslam ahlak sistemine dayalı aksiyomlar, bireysel ve toplumsal düzeyde uyum ve adaleti sağlamada yol gösterici bir model sunmaktadır. Sonuç olarak, İslam ahlak ekonomisinin modern dünyada alternatif bir ekonomik paradigma olarak daha fazla görünürlük kazanması gerektiği sonucuna varılmıştır.

高分子材では，発生した局所的な変形（くびれ）が試験片平行部を伝播する挙動がしばしば観察される．このような挙動が生じるためには，くびれが伝播した部分が加工硬化している必要がある．しかし，先行研究1)では，くびれの伝播挙動が生じるPC材において，伝播部の軟化が確認された．本研究では，PC材同様にくびれの伝播挙動が確認されている2)PP材を新たに追加し，精密万能試験機AUTOGRAPH AGS-H 5kN（島津製作所製）を使用し，平板型の試験片で準静的引張試験を行った．その際，試験片の板幅面及び板厚面の変形画像を撮影し，デジタル画像相関法を用いて縦ひずみ及び横ひずみを計測した．結果として，PC材と同様に発生したくびれが試験片平行部を伝播する様子が確認された．また，くびれの伝播に伴う試験体の強度変化を把握するためにビッカース硬さ試験を実施した．結果として，PC材と同様にくびれの伝播部の軟化が確認された．PC材，PP材共にくびれの伝播に伴い伝播部が軟化する結果となったが，これはくびれの伝播条件に矛盾する．その原因として①硬さの異方性，②再降伏の早期化，が考えられた．①材料の異方性により断面では硬化している可能性が考えられたが，断面と表面の硬さに差がなく，断面においても伝播部の軟化が確認されたため，伝播部の軟化原因は材料の異方性によるものではないことが分かった．②同一試験片に対して複数回の引張試験を実施したところ，初回負荷時に比べ2回目以降の負荷では，低い応力で再降伏することが確認された．そのため，硬さ試験ではこの低い応力での再降伏点が反映され軟化につながっていると考えられる．

The microstructural change and fracture by repeated gas nitriding and gas nitrocarburizing of SUS304 jig were investigated in this study. It was found that an oxide layer which was formed owing to high-temperature oxidation of the microstructure near the surface, was easily detached from the surface layer. Also, many micro voids in the oxide layer were observed. Beneath the oxide layer, a compound layer containing mainly nitrides was identified. A carbon diffusion region was observed in the matrix adjacent to the interface between the compound layer and the matrix. It was considered that the fine voids and uneven surfaces induced under loading stress during both treatments were the crack initiation points, which coalesced for the development of cracking. The fractured surface exhibits a sequence of brittle and ductile fracture patterns as the microstructure changes from the surface to the interior.

We report on a thermodynamic analysis of oxide vapor phase epitaxy (OVPE) of GaN. We first calculate equilibrium partial pressures of gases for the initial partial pressures of Ga2O, NH3, and H2 as well as the growth temperature. To estimate the growth rate of a GaN crystal, we then define the supersaturation amount determined by the equilibrium and initial partial pressures. In the calculation, the growth rate is significantly influenced by the initial partial pressures of Ga2O and NH3, while it is almost independent of the initial partial pressure of H2 and the growth temperature. Subsequently, we experimentally grow GaN crystals under same conditions as in the thermodynamic analysis. In the range of conditions in this work, the experimental growth rates are nearly consistent with the growth rates predicted by the thermodynamic analysis for all experimental parameters. Thus, the results showed that a high value of the supersaturation amount is advantageous for high-speed growth. Furthermore, we define the supersaturation ratio and investigate the correlation between this parameter and the surface coverage of the polycrystal. The surface coverage of the polycrystal is confirmed to roughly decrease as the value of the supersaturation ratio decreases. Thus, the results showed that a low value of the supersaturation ratio is advantageous for polycrystal-free growth. Finally, we use the thermodynamic analysis to explore the optimal conditions for high-speed and polycrystal-free growth. This revealed that the optimal OVPE growth conditions are both a high partial pressure of Ga2O and a low partial pressure of NH3.

Nylon 66 is an engineering plastic with the advantageous characteristics of light weight, heat resistance, high strength, and high rigidity; it has been used in automobile parts as a substitute for aluminum alloys. There have also been many studies on the mechanical properties of nylon 66. However, the flow stress in nylon 66 after necking has not been thoroughly investigated yet due to the difficulty in identifying local stress. In this study, a flow stress optimization method based on the digital image correlation (DIC) method and response surface method, is proposed. The averaged true stress–true plastic strain curve is first obtained by a quasi-static tensile test via DIC. Subsequently, the flow stress is optimized via the response surface method to obtain the actual flow stress state after necking. The accurate flow stress in the specimen can be obtained based on the relationship between the global load force and distance between the two shoulders of the specimen grip parts that is unaffected by the cross-sectional area change during necking. The results indicate that the average true stress recorded from the experiment overestimates the flow stress after necking. The optimized flow stress exhibits the maximum decrease of 9%. The accuracy of the optimized flow stress is evaluated by comparison with the true strain distribution on the specimen that is accurately measured via DIC.

To assist the advancement of tsunami risk assessment methods for nuclear power plants, requirements for the generation of artificial tsunami waveforms crucial for close linkage between the probabilistic tsunami hazard analysis and tsunami fragility analysis were first listed. Then, basic studies were conducted to model the phase and amplitude spectra of waveforms observed during the 2011 Tohoku earthquake tsunami. Consequently, the average values of the group delay times and amplitude spectrum for each period band were confirmed to be effective for each modeling. Finally, based on these requirements and results of the basic studies, a technique for generating artificial tsunami waveforms using a statistical method was proposed.