Ocular conditions and dry eye due to traditional and new forms of smoking: A review

Addiction to cigarette smoking has high prevalence rates recorded worldwide. Smoking has been linked to several life-threatening systemic conditions such as cancer, heart attack and stroke, in addition to a range of ocular pathologies. In recent years, electronic cigarettes (EC) have emerged as alternatives to smoking. ECs are nicotine delivery devices which produce an aerosol by heating, rather than combusting, a liquid which contains nicotine, flavours and preservatives. This review focuses on the association of traditional and new forms of smoking with dry eye disease, contact lens wear and four other common ocular diseases: cataract, age-related macular degeneration, glaucoma and Graves’ ophthalmopathy. It is concluded that smoking and vaping appear as a risk factor for the aforementioned ocular conditions. An evidence-based, clear link between cigarette smoking, or EC vaping and ocular problems is yet to be discovered.     

A direct numerical simulation of transition phenomena in a mixed convection channel flow

This study intends to provide an increased understanding of the laminar-turbulent transition phenomena for the buoyancy-assisted heated vertical channel flow during the early transient stage. The spectral method with weak formulation is applied in the direct numerical simulation. Initial disturbances consist of the finite-amplitude two-dimensional TS wave and a pair of three-dimensional oblique waves for the K-type disturbances. The results from the harmonic energy competitions of different wave modes show that for the buoyancy-assisted heated flow, the (k_x=1, k_z=1) or (1,1) and (1,0) modes would gain energy immediately and start to rise at almost the same rate. This phenomenon is different from that of the buoyancy-opposed flow, where the (1,1) mode decays slowly in the beginning until other modes gain enough energy and then it begins to grow quickly and overtakes the (1,0) mode after a short time period. These different transition patterns match with the experimental results that the flow transition is supercritical and subcritical for the buoyancy-assisted and -opposed flows, respectively. Buoyancy-assisted heated flow transition follows the general trend of an isothermal flow in the beginning, but the thermal-buoyant force is crucial in accelerating the instability and also causing notable differences during the subsequent transition process. All of the results for the vortex structures development, kinetic energy budget of the disturbances, flow visualization by tagged fluid particles, and the local temperature fluctuations are consistent in pointing to a clear pattern for the buoyancy-assisted heated flow transition.     

水对植物纤维水泥复合板生产的影响

研究了水对植物纤维水泥复合板性能的影响。选择合适的水分可以提高板材静弯曲强度,减小板材变形。     

环氧-丙烯酸热变色涂料的研究

用性能优良的环保型的水性环氧-丙烯酸树脂作主要成膜物质,将无机热变色材料分散于环氧-丙烯酸树脂中,制成环氧-丙烯酸热变色涂料.结果表明,所得到的环氧-丙烯酸热变色涂料的性能优良,受热变色效果明显.     

冷库地坪防冻臌机械通风的传热计算

设计手册中关于使用机械通风防止冷库地坪冻臌的参数（风道直径、间距及长度）仅是推荐值，它忽略了地坪结构、土壤温度和外界空气温度对通风系统节能的影响，因而造成地基土壤的热损失和冷库负荷的增大。从冷库节能和冷库建筑安全使用出发，对采用机械通风防止地坪冻臌进行了传热分析，提出了在传热计算中参数的合理选择和通风系统的设计方法。     

热型连铸单晶铜工艺参数对铸棒表面质量的影响

在自行设计，制造的横引式热型连铸设备上对影响连铸过程的各工艺参数进行试验，并就各工艺参数对铸件表面质量的影响机理进行了分析。结果表明，各工艺参数主要是通过影响固液界面在型口中的位置来影响铸棒的表面质量，只有对各工艺参数进行合理匹配，才能得到表面光滑的铸棒，此外，液位高度变化即液位波动，也会对铸棒的表面质量产生 一定影响。     

Molecular weight averages as criteria for quality assessment of heated oils and fats

A simple method for quality assessment of heated oils and fats is described. The proposed method involves precise determination of molecular weight averages (MWA)viz., the weight average molecular weight ( ), the number average molecular weight ( ) and the Z-average molecular weight ( ) by high performance size exclusion chromatography (HPSEC) and their quantitative correlation to percent polar material obtained by column chromatography (CC). Change in MWA on heat treatment of fourteen different edible oils and fats at 180° ± 2°C for eight 8-hr days is studied. Relative standard deviations and regression coefficients of correlation between MWA and their ratios ( , { }, { }, { }, { } and { )vs percent polar material have been reported. Probable discard time was predicted for all the oils based on the above-mentioned correlations and also from the percent of high molecular weight (H. Mwt) species formed. It was observed that the oils which are generally recommended for coronary patients deteriorated faster. A possibility of extending this methodology to the frying oils is suggested. Part of the work was presented at “40th Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy” at Georgia World Congress Centre, USA, 1989. IICT Communication No. 2630.     

食品级柠檬酸生产过程中的干燥和空气净化

阐述了食品级柠檬酸生产中产品干燥和空气净化的特殊要求及设计特点。     

基于Fluent的双加热湿度传感器传热性能分析

双加热湿度传感器可实现大气湿度连续探测.液滴、冰晶等水凝物覆盖在双加热湿度传感器表面,容易导致其测量精度和响应速度降低.为了提高测量精度和响应速度,有必要对双加热湿度传感器进行除湿处理.采用Pro/E建立4种尺寸的双加热湿度传感器三维模型;利用ICEM CFD中模块化的方法对模型进行分网,得到了较高的网格质量,降低了计算时间,提高了计算精度;利用Fluent稳态分析模拟出2只湿度传感器不同间距下的相互影响情况,瞬态分析模拟出升温时间和降温时间特性.根据仿真结果,提出高空和低空2种模式加热策略.     

天然气年产4万吨甲醇联产年产2.5万吨合成氨代替重油设计

利用现生产重油制氨的1000m~3(V_n)(O_2)/h空分,建设天然气并联换热蒸汽转化串纯氧部分氧化制甲醇和氨两用合成气,成为4万吨/年甲醇联产2.5万吨/年氨的生产单元组合,既节能节气、降低投资和生产消耗及成本,又充分利用现有设备发挥生产能力,同时还可增加产品和产量。