Effect of hydraulic retention time and pH on oxidation of ferrous iron in simulated ferruginous acid mine drainage treatment with inoculation of iron-oxidizing bacteria

The effect of hydraulic retention time (HRT) and pH on the biooxidation of ferrous iron during simulated acid mine drainage (AMD) treatment was investigated.The simulated AMD was highly acidic (pH 2.5), rich in iron (about 1700 mg/L) and copper (about 200 mg/L), and contained high concentrations of sulfate (about 4700 mg/L).The biooxidation of ferrous iron was studied in a laboratory-scale upflow packed bed bioreactor (PBR).The HRT was shortened stepwise from 40 h to 20 h, 13 h, and 8 h under the acidic environment at a pH value of 2.2.Then, the influent pH value was changed from 2.2 to 1.2 at a constant suitable HRT.Physiochemical and microbial community structure analyses were performed on water samples and stuffing collected from the bioreactor under different conditions.The results indicate that the efficiency of ferrous iron oxidation gradually decreased with the decrease of HRT, and when the HRT exceeded 13 h, ferrous iron in AMD was almost completely oxidized.In addition, the best efficiency of ferrous iron oxidation was achieved at the influent pH value of 1.8.Microbial community structure analyses show that Leptospirillum is the predominant genus attached in the bioreactor, and low influent pH values are suitable for the growth of Leptospirillum.

Very Low, Real-Time Rate of Urinary Retention after Intradetrusor Botox^&regfor Non-Neurogenic Overactive Bladder

Introduction: According to the most recent AUA/SUFU guidelines, intradetrusor onabotulinumtoxinA (BTN/A) is a standard, evidence strength grade B, third line treatment option for refractory non-neurogenic overactive bladder (OAB). Urinary retention is the most common clinically significant reported side effect ranging from 5.4% to 43% in previous studies. The aim of this study was to investigate the real-time rate of urinary retention in patients treated with BTN/A for refractory non-neurogenic OAB in a multi-institutional study. Methods: Retrospective chart review identified 71 patients who were treated with 100U BTN/A for refractory non-neurogenic OAB from August 2011 to July 2015 at two institutions. Using a flexible cystoscope, 100U Botox&reg reconstituted with 10 ml normal saline was administered. Injections of 1 ml (10 units/ mL) were administered in 10 evenly distributed sites sparing the trigone. Pre and post BTN/A post-void residuals (PVR) were reviewed. Urinary retention was defined as PVR > 200 mL requiring clean intermittent catheterization (CIC). Results: After exclusion, the study group consisted of 66 patients with a mean age of 67 years and 30% were men. Mean pre and post-procedural PVR were 14.06 mL and 69.21 mL. Eight patients (12.12%) were noted to have elevated PVR > 200 mL post injection however only one patient (female) required initiation of CIC. The rate of urinary retention was 1.5% (N = 1). There was no correlation with age, history of previous radiation, diabetes or prior use of a neuromodulator device. Conclusions: To the best of our knowledge, this is the first study to demonstrate a very low risk of real-time urinary retention rates in appropriately selected patients treated with BTN/A for refractory non-neurogenic OAB outside of a clinical trial setting.

The Effect of Hydraulic Retention Times and Loading Rates on the Removal of Pollutants from Fish Processing Wastewater by Anaerobic Process

Anaerobic treatment model treats fish processing wastewater to be necessary for a small and medium factory that is very popular in Vietnam and other countries.Several techniques have been proposed.However,they are quite expensive and hard to operate,especially in remote areas.In this study,the hydraulic retention times(HRT)including 3,5,and 7 hours with a various organic loading rate of 1.5 to 6.5 kg COD/m3/day were investigated.Biomass concentration as mix-liquor volatile suspended solid(MLVSS)in the model is at 6,000 to 9,000 mg/L.On the basis of the result the optimal HRT with a 4.0 kg COD/m3/day organic loading rate was 8 hours which BOD5,COD removal efficiency were 92.18,87.36 percent respectively.By the end of the optimal hydraulic retention times,the total methane gas volume as a by-product was collected with 2.6 liters.

Study on the Retention Rate of Green Tea Catechins Components and Tea Polyphenol by Different Processing Technology

The aim of this research was to explore the effect of fixation,rolling,and drying processing technology on the retention rate of green tea catechins components and tea polyphenol.Different fixation processes(rotary drumfiring,microwave,steam-blasting),rolling process(weight of rolling,gently press rolling and traditional rolling),drying process(stove drying,roasting dehydration,baked fried drying) were adopted.The effect of different tea processing technology on the retention rate of catechins component and tea polyphenol was analyzed.It showed that the microwave fixation process,gently press rolling process,baked fried dry process were beneficial to keep high levels of EGCG,C,EGC,EC,ECG.

APPLICATION OF BORON MODIFIED SILICA SOL ON RETENTION AND DRAINAGE

In this paper it was studied that these dosage effects of CPAM, cationic starch?boron modified silica sol(BMS), Al2(SO4)3, pH value and electrolyte on the retention and drainage of different microparticulate systems including CPAM, cationic starch and boron silica sol. The research results indicated that CPAM had no good retention when used with boron silica sol. The best retention efficiency was the microparticulate system of CPAM + cationic starch with boron modified silica sol; Secondly was that of cationic starch with boron modified silica sol; The worst was that of CPAM with boron modified silica sol. The retention efficiency had no relation with the addition order between CPAM and cationic starch. It was also found that the microparticulate retention system of boron modified silica sol could be used in alum-rosin sizing and in acidity, neutral or alkaline papermaking conditions. This system also could be used with close circulate water so that it could reduce the water pollution and waste.

STDUY ON RETENTION AND DRAINAGE PROPERTIES OF THE HIGH SUBSTITUTED DEGREE CATIONIC STARCH

This paper deals with the retention and drainage properties of the high substituted degree cationic starch (HCS) prepared by half-dry process. The experiments show that HCS has remarkable effects on filler retention and drainage in papermaking industry. With the degree of substitution (DS) of HCS increasing, the effects on filler retention and drainage increase. When the DS of HCS is 0.509 and the dosage is 0.08%, the freeness decreases about 12oSR and the filler retention is 79.82%.

APPLICATION OF CATIONIC POLYMERIC MICROPARTICLES ON RETENTION AND DRAINAGE

The conditions of preparation and performance of a new structure of cationic organic polymeric micropaticles (CPMP) mainly composed of styrene and DADMAC were studied. And its application on retention and drainage on bleached hardwood pulp was investigated and compared with that of APAM and CPAM. The results show that the retention and drainage of CPMP on pulp is in positive proportion to the rise of the potential of the solution, and the first-pass retention ratio of bleached hardwood pulp goes up with the increase of the CPMP content. The functions of CPMP and CPAM are affected less by the shear force and the pH value of the system compared to that of APAM, and effect on retention of CPMP3 is appropriate to that of CPAM, but superior to that of APAM.

Regulation of MRI contrast and cellular retention time by cellular interfacial distribution of Gd agents:Implications for stem cell tracking

Human mesenchymal stem cells(hMSCs)were labeled with Dotarem or(Gd-DOTA)2-EM7(EM7Gd2)via electroporation(EP).Cellular transmission electron microscopy(TEM)reveals free distribution of Gd agents and formation of EM7Gd2 clusters in the cytosol.Cellular magnetic resonance imaging(MRI)reveals that the free Gd agents induce MRI signal enhancement effect due to its fast exocytosis and subsequent interaction with intercellular water molecules.The EM7Gd2 clusters exhibits a longer intracellular retention time and induce a persistent MRI signal reduction effect.The cellular MRI results are interpreted by taking into account both T1 and T2 relaxation rates and their correlation with cellular binding structures of Dotarem and EM7Gd2.

STUDY ON A NEW NONIONIC MICRIOPARTICLE RETENTION SYSTEM

The retention and drainage performances of microparticle retention system were studied in this paper, through measuring the improvement of beaten degree and retention ratio of slurry. The effects the retention system on paper sheet were discussed by measuring physical properties of paper. Compared with the influence of Hydrocol system (CPAM/bentonite) on the aspects of retention aid and drainage properties as well as increased product cost per ton paper, the developed nonionic system has some superiority and better practicability.

Optimizing feeding regimen of replacement gilts to improve their reproductive performance and retention rate of their first 2 parities

The effects of age,body weight(BW),and backfat thickness(BF)of replacement gilts at first estrus and first mating on their subsequent reproductive performance and retention of their first 2 parities as sows was evaluated.A total of 3,025 Danish replacement gilts were categorized by farm(allocated to 4 farms),cross combination,age,BW and BF at first estrus and first mating,estrous cycle number at first mating,and flush feeding before first mating.The result shows that all the factors mentioned above were significantly associated with reproductive performance and retention rates of the first 2 parities.Farm 3 had more piglets born alive per litter(BA)(P<0.05).Farms 3 and 4 had more healthy piglets per litter(HP)(P<0.05).Farm 4 had the most piglets weaned per litter(PW)(P<0.05).Landrace×Landrace×Yorkshire(L×L×Y)replacement gilts had the most total piglets born per litter(TB),BA,HP,PW and a higher retention rate of the 2 parities than Landrace×Yorkshire(L×Y)replacement gilts(P<0.05).In addition,flush feeding before first mating had the most TB,BA,HP,PW,and a higher retention rate of the 2 parities than no flush feeding(P<0.05).Because the effects of replacement gilts rearing parameters on reproductive performance traits differed,we used 100 replacement gilts as a unit and the total number of weaned piglets from the first 2 parities as a new index.Replacement gilts undergoing their first estrus between 180 and 210 d of age at 115 to 124.9 kg BW and 14 to 15 mm BF had significantly higher reproductive indexes for their first 2 parities per 100 replacement gilts.Replacement gilts that mated between 210 and 230 d of age at 140 to 149.9 kg BW and 15 to 16 mm BF had optimal reproductive indexes.These results provide a new insight into the complex relationships among these reproductive performance traits and may help guide successful management of replacement gilts as a pivotal starting point for future fertility and longevity of rearing herds.

Facial aesthetic fat graft retention rates after filtration, centrifugation, or sedimentation processing techniques measured using three-dimensional surface imaging devices

Objective:How to increase the long-term retention rate of autologous fat grafting has been widely discussed.This study aimed to evaluate long-term fat graft retention rates for the most widely used fat processing methods in the area of facial esthetic surgery,including centrifugation,filtration,and sedimentation,using three-dimensional (3D) imaging.Data Sources:PubMed,Embase,Wiley/Cochrane Library,and Web of Science databases were comprehensively searched from inception to July 2018 according to the guidelines of the American Society of Plastic Surgeons Fat Graft Task Force Assessment Methodology.Study Selection:Articles were screened using predetermined inclusion and exclusion criteria.Data collected included patient characteristics,follow-up devices,fat grafting techniques,and clinical outcomes.Patient cohorts were pooled,and fat graft retention rates were calculated.Complications were summarized according to different clinical characteristics.Results:Of 77 articles,10 clinical studies met the inclusion criteria and reported quantified measurement outcomes with 3D imaging which provide precise volumetric data with approximately 2% standard deviation compared to real volumes.Data of 515 patients were included.Fat grafting retention varied from 21% to 82%.We found filtration and centrifugation techniques could result in better retention outcomes.However,retention varied within each processing technique,with no significant difference among the 3 techniques.Twenty-two complications were reported among 515 patients,including donor-site hematoma (1 case),mild postoperative erythema (2 cases),mild volumetric asymmetries (2 cases),chronic edema (2 cases),overcorrection (2 cases),skin irregularity (6 cases),and headache or dysesthesia (7 cases).Conclusions:Filtration and centrifugation techniques may result in better fat grafting retention outcomes than gravity sedimentation;however,more accurate statistical evidence is needed.Controversies continue to exist with respect to the performance of the different fat-processing techniques in fat graft retention.

Extensive experimental investigation of the effect of drainage height and solvent type on the stabilized drainage rate in vapour extraction (VAPEX) process

The low cost of the injected solvent,which can be also recovered and recycled,and the applicability of VAPEX technique in thin reservoirs are among the main advantages of VAPEX process compared to thermal heavy oil recovery techniques.In this research,an extensive experimental investigation is carried out to first evaluate the technical feasibility of utilization of various solvents for VAPEX process.Then the effect of drainage height on the stabilized drainage rate in VAPEX process was studied by conducting series of experiments in two large-scale 2D VAPEX models of 24.5 cm and 47.5 cm heights.Both models were packed with low permeability Ottawa sand(#530)and saturated with a heavy oil sample from Saskatchewan heavy oil reservoirs with viscosity of 5650 mPa s.Propane,butane,methane,carbon dioxide,propane/carbon dioxide(70%/30%)and propane/methane(70%/30%)were considered as respective solvents for the experiments,and a total of twelve VAPEX tests were carried out.Moreover,separate experiments were carried out at the end of each VAPEX experiment to measure the asphaltene precipitation at various locations of the VAPEX models.It was found that injecting propane would result in the highest drainage rate and oil recovery factor.Further analysis of results showed stabilized drainage rate significantly increased in the larger physical model.

Effect of preoperative biliary drainage on surgical results after pancreaticoduodenectomy in patients with distal common bile duct cancer:Focused on the rate of decrease in serum bilirubin

AIM: To examine if the rate of decrease in serum bilirubin after preoperative biliary drainagecan be used as a predicting factor for surgical complications and postoperative recovery after pancreaticoduodenectomy in patients with distal common bile duct cancer.METHODS: A retrospective study was performed in 49 consecutive patients who underwent pancrea-ticoduodenectomy for distal common bile duct cancer. Potential risk factors were compared between the complicated and uncomplicated groups. Also, the rates of decrease in serum bilirubin were compared pre- and postoperatively. RESULTS: Preoperative biliary drainage (PBD) was performed in 40 patients (81.6%). Postoperative morbidity and mortality rates were 46.9% (23/49) and 6.1% (3/49), respectively. The presence or absence of PBD was not different between the complicated and uncomplicated groups. In patients with PBD, neither the absolute level nor the rate of decrease in serum bilirubin was significantly different. Patients with rapid decrease preoperatively showed faster decrease during the first postoperative week (5.5 ± 4.4 μmol/L vs -1.7 ± 9.9 μmol/L, P = 0.004).CONCLUSION: PBD does not affect the surgical outcome of pancreaticoduodenectomy in patients with distal common bile duct cancer. There is a certain group of patients with a compromised hepatic excretory function, which is represented by the slow rate of decrease in serum bilirubin after PBD.

Kinetic Rate Constant of Liquid Drainage from Colloidal Gas Aphrons

实验方程适合的一个运动模型被建议了描述液体排水行为。率常数(k 液体排水方程的 d ) 能从上述实验方程被获得。在这篇论文，胶体的煤气的 aphrons ( CGA )的稳定性，钠 dodecyl 苯硫酸盐( SDBS )的集中的效果， dodecyl trimethylammonium 溴化物( HTAB )和 polyoxyethylene 山梨糖醇酐 monolaurate ( Tween-20 )，温度，激动人心的速度，激动人心的时间，并且 k 液体排水的 d 进一步被调查。结果证明 Arrhenius 方程能成功地被用来描述在 k d 和绝对温度(T) ，和表面活化剂，激动人心的速度，激动人心的时间和咸度的集中也在 k d 。最后， CGA 排水机制作为时间的功能从液体排水的率的分析被解释。

不同助留体系对装饰原纸二氧化钛复合填料留着效果的影响

本研究分别分析了单元助留体系阳离子聚酰胺环氧氯丙烷树脂(PAE),双元助留体系PAE/阴离子聚丙烯酰胺(APAM)、PAE/膨润土(MMT)、PAE/阳离子聚丙烯酰胺(CPAM),三元助留体系PAE/CPAM/APAM、PAE/CPAM/MMT对装饰原纸TiO_(2)/滑石粉复合填料留着效果的影响。确定了各个体系的最佳添加量,并筛选出助留效果最好的助留体系。结果表明,当PAE添加量2.0%、CPAM添加量0.08%、MMT添加量0.6%时,组成的PAE/CPAM/MMT三元助留体系留着效果最佳,此时,浆料和填料留着率分别为89.5%和65.0%,纸张的不透明度、白度及匀度分别为98.5%、86.6%和91。

基于炉缸渣铁滞留量的高炉炉缸活性研究

针对国内外对炉缸活性表征不明晰的问题,建立以炉缸渣铁滞留量表征炉缸活性的模型,定量分析高炉操作参数对炉缸活性的作用比重,并提出提高炉缸活性的操作手段。结果表明:①渣铁焦物性对渣铁滞留率的影响顺序为:铁水温度>CSR>焦炭粒度>CRI>炉渣碱度>镁铝比;②去除滞留率对滞留量的影响,高炉操作参数对渣铁滞留量的影响顺序为:风量>铁口深度>风温>风压>喷煤量>氧气量;③高炉生产中,可采用原燃料粒级及性能管控技术、高风速大动能操作技术、渣铁流动控制技术、渣铁排放管控技术高效调控炉缸活跃状态。

桑葚花青素的稳定性及降解动力学研究

桑葚花青素不稳定,外界因素的变化容易造成其降解。该试验以花青素保留率和颜色变化为评价指标,考察了光照、pH值、温度、添加剂、金属离子等因素对桑葚花青素稳定性的影响并探究其降解动力学。结果显示:室外光照加速了花青素的降解,k值由避光条件的1.80×10^(-2)升高至14.12×10^(-2),t_(1/2)由避光条件的38.5 h降至5.2 h。酸性环境(pH值1.00,3.00)下花青素的稳定性高,中性(pH值7.00)、碱性(pH值9.00)时花青素易发生降解,96 h后花青素的保留率分别降至83.25%、72.44%,颜色由酸性时的红色分别变为灰绿色、墨绿色。花青素在80,100℃分别放置10 h后ΔE^(*)分别变为3.4097,6.1928,红色褪去,花青素的保留率仅为65.39%、38.83%。酸度剂(柠檬酸)对花青素有明显的稳定和增色作用,防腐剂(山梨酸钾、苯甲酸钠)、抗氧化剂(抗坏血酸)加速了花青素的降解。Al^(3+)、Fe^(3+)、Fe^(2+)等金属离子的加入在一定程度上破坏了花青素的结构,颜色分别变为蓝紫色、黄褐色、蓝黑色。桑葚花青素的贮藏稳定性较差,适合低温、避光和酸性环境,并避免接触防腐剂、抗氧化剂等添加剂和铁、铝制品。该试验结果为花青素的贮藏、加工和应用提供了基础数据和理论依据。

疏水α-Al_(2)O_(3)陶瓷膜特性表征及温差驱动能力研究

疏水陶瓷膜在膜蒸馏领域具有突出优势,可拓宽膜蒸馏应用场景.采用新方法制备疏水α-Al_(2)O_(3)陶瓷膜,表征形貌特征、疏水性能、接枝有效性及宽温域热稳定性,揭示温差对单位温差驱动能力的影响规律,测定疏水陶瓷膜蒸馏过程的离子截留率.研究结果表明:疏水陶瓷膜表面形成了较规律的粗糙结构,疏水性能优异;疏水陶瓷膜表面的1H,1H,2H,2H-全氟癸基三乙氧基硅烷发挥了疏水作用,且具有较好的高温热稳定性;基于原水温度的单位温差驱动能力(e_(c))随温差(ΔT)按-0.7356次幂函数规律负相关变化,而基于冷却水温度的单位温差驱动能力(e_(r))随ΔT按1.74589次幂函数规律正相关变化;疏水陶瓷膜蒸馏过程对所有被测离子的截留率均大于99.96%.该研究对指导制定疏水陶瓷膜蒸馏运行策略具有重要意义.

未来30年中国耕地和高标准农田分布的省级预测

科学预测中国未来耕地和高标准农田分布对于保障我国粮食安全和提高耕地质量具有重要意义。该研究假设未来各省份耕地和高标准农田占全国总面积比例不变,根据各省份耕地和高标准农田实际面积、未来全国耕地及各省份高标准农田规划面积等数据,基于最小二乘法的二次多项式拟合预测未来30 a全国及各省份耕地面积和高标准农田面积,进而预测未来各省份耕地面积保有率和高标准农田占耕地比例。结果表明:(1)到2050年,我国耕地面积稳定在1.20×10^(8)hm^(2),耕地面积保有率稳定在100%,高标准农田面积达到1.03×10^(8)hm^(2),高标准农田占耕地比例从2020年的43.59%增长到2050年的85.89%,增长近一倍。(2)七大区域中,黄淮海区、长江中下游区、东南区的高标准农田占耕地比例较高,在2020年均已达到70%以上,东北区、西北区、青藏区、西南区高标准农田占耕地比例则处于40%~60%之间。到2050年,受耕地比例稳定中略有下降的趋势影响,黄淮海区、长江中下游区、东南区、青藏区高标准农田占耕地比例均达90%以上,东北区、西北区、西南区则处于70%~90%之间。(3)从各省份来看,江西省、浙江省、福建省、广东省等南方省份的高标准农田建设比例较高,而内蒙古自治区、黑龙江省、辽宁省、吉林省、山东省等北方省份的耕地面积保有率较高。研究得到的耕地面积及其保有率、高标准农田面积及其占耕地比例等指标的分省份预测值可以为未来相关部门制定国土空间规划等提供科学依据,也可以为未来耕地布局和农田利用等研究提供分省份的总量参考。

蜂蜡添加量对鱼油凝胶宏观性质及微观结构的影响

鱼油富含高营养价值的ω-3型多不饱和脂肪酸,由于其容易氧化,因此不利于产品的生产和加工。油凝胶具有良好的氧化稳定性、保油性、低脂肪的特点,既满足了降低动物脂肪的需求,又提高了产品品质和营养价值,是高营养、低热量的脂肪替代物。以蜂蜡为凝胶剂,沙丁鱼油作为基础油料制备油凝胶,分析蜂蜡添加量对沙丁鱼鱼油凝胶的外观形态、保油率、质构特性、流变性质及微观结构的影响。结果表明:蜂蜡基鱼油凝胶为β′晶型,添加蜂蜡促使晶体结构的形成,也提高了蜂蜡基鱼油凝胶的保油率、硬度、凝胶强度,且蜂蜡添加量为8%及以上时保油率达到99%。G′不随频率的变化而发生改变,说明蜂蜡基鱼油凝胶是一种强凝胶,静态流变学图像显示该凝胶出现剪切稀化现象。蜂蜡添加量在6%~10%时,蜂蜡基鱼油凝胶与猪油的质构特性与流变行为相似,研究结果为鱼油凝胶替代猪油提供了理论支持。