Upflow Anaerobic Filter for the Treatment of Wastewater from a Natural Rubber Latex Concentration Unit

In this study, wastewater from a centrifuge rubber latex concentration unit was experimentally treated by an up-flow anaerobic filter (UAF) at variable hydraulic detention time to investigate the COD removal efficiency and the gas production rate. The UAF reactors were made of PVC pipe with an inside diameter of 9.5 cm, 180 cm in height, with a bed volume of 12.8 L, and filled with polyethylene media. The initial COD concentration of wastewater was in the range 4620 - 10400 mg.L-1. HRTs were controlled at 20 days, with the organic loading rate varying from 2.9 to 10.5 kg.day.m-3. The findings show that the COD removal efficiency of the system was in the range of 85% to 92% for the varying organic loading rates. In addition, the specific methane production rate varied from 8.2 to 14 L of CH4 produced/g of COD destroyed/day for the different organic loading rates.

The Nature of Ligand Efficiency

<p>Ligand efficiency is a widely used design parameter in drug discovery. It is calculated by scaling affinity by molecular size and has a nontrivial dependency on the concentration unit used to express affinity that stems from the inability of the logarithm function to take dimensioned arguments. Consequently, perception of efficiency varies with the choice of concentration unit and it is argued that the ligand efficiency metric is not physically meaningful nor should it be considered to be a metric. The dependence of ligand efficiency on the concentration unit can be eliminated by defining efficiency in terms of sensitivity of affinity to molecular size and this is illustrated with reference to fragment-to-lead optimizations. An alternative to ligand efficiency for normalization of affinity with respect to molecular size is presented. Group efficiency and fit quality are also examined in detail from a physicochemical perspective. The importance of examining relationships between affinity and molecular size directly is stressed throughout this study. </p>

The Nature of Ligand Efficiency

<p>Ligand efficiency is a widely used design parameter in drug discovery. It is calculated by scaling affinity by molecular size and has a nontrivial dependency on the concentration unit used to express affinity that stems from the inability of the logarithm function to take dimensioned arguments. Consequently, perception of efficiency varies with the choice of concentration unit and it is argued that the ligand efficiency metric is not physically meaningful nor should it be considered to be a metric. The dependence of ligand efficiency on the concentration unit can be eliminated by defining efficiency in terms of sensitivity of affinity to molecular size and this is illustrated with reference to fragment-to-lead optimizations. An alternative to ligand efficiency for normalization of affinity with respect to molecular size is presented. Group efficiency and fit quality are also examined in detail from a physicochemical perspective. The importance of examining relationships between affinity and molecular size directly is stressed throughout this study. </p>

The Effect of Tofu Liquid Waste on Mortality and Histopathology of Goldfish (Cyprinus carpio) Kidney as a Biology Alternative Material Concept for Senior High School X Grade

Liquid waste of tofu is a liquid-byproduct of tofu production proces which is known as "whey". Most of the "whey" can not be utilized. Thus, the liquid waste of tofu that flowed directly into the river, without any extent process to neutralize will cause the death fish. The effect of tofu liquid waste can be observed throughout the histopathological observation (especially the kidneys). This study aims to determine the effect of tofu liquid waste on mortality and histopathology of goldfish kidney. This study employed an experimental method using goldfish with the size of 8-12cm. The data collection was started by preliminary test in which the liquid concentration were of 0 ml/L, 0,1 ml/L, 1 ml/L, 10 ml/L, and 100 ml/L, which then the real tests were conducted by using RAND method to obtain the concentration of 0 ml/L, 32 ml/L, 56 ml/L, 75 ml/L, and 87 ml/L. The LC50 goldfish observational data have been analyzed by using Probit Model Finney program "Quant"; meanwhile, the goldfish kidney taken per concentration unit as samples for histopathological observation. The results showed that the tofu liquid waste gave significant impact on mortality and the occurrence of goldfish kidney damage (histopathology), such as hemorrhage, congestion, and necrosis. Based on the data, this study can be recommended as enrichment of biology alternative material for X grade of senior high school at KD 3.10 i.e. to analyze the data of environmental changes and the impact of such changes for life.