Effects of level soil bunds and stone bunds on soil properties and its implications for crop production: the case of Bokole watershed, Dawuro zone, Southern Ethiopia

Level soil bunds (LSB) and stone bunds (SB) have been widely implemented in the Bokole watershed since 2000 through support of the World Food Program (WFP). However, the performance of them against the target of the structure has not been studied. This study analyzed the effect of LSB and SB on selected soil properties, when compared with nonterraced cropland. The Bokole watershed was divided into two units. From upper watershed, three croplands with LSB (aged 4, 6, and 9 years) and three nonterraced croplands each adjacent to one of the LSB were selected. Similarly, in lower watershed, SB aged 4, 6, and 8 years and three nonterraced croplands each adjacent to one of the SB were selected. From each cropland with LSB and SB, three composite soil samples (rep licates) were collected systematically in X designed rectangular plot. From each nonterraced cropland, three composite soil samples (replicates) were collected in X designed square plot. A total of 36 soil samples were analyzed for Soil Organic Carbon (SOC), Total Nitrogen (TN), Available Phosphorus (AP), Available Potassium (AK), pH, and Cation Exchange Capacity (CEC) following standard laboratory procedures. Most soil parameters were not significantly different in cropland with LSB and SB compared to nonterraced. However, in LSB aged 4 years and SB aged 6 years AP and pH were significantly less than their adjacent-nonterraced cropland. In SB aged 8 years, SOC, AP, AK, and pH were also significantly less than adjacent-nonterraced cropland. Past erosion, and past land uses are likely factors contributed to the observed result. It was inferred that the mean con tribution of LSB and SB alone for crop production with regard to analyzed soil parameters was not significant in the considered sites. Additional soil fertility management practices should be incorporated for better effect.

Alleviated photoinhibition on nitrification in the Indian Sector of the Southern Ocean

Nitrification,a central process in the marine nitrogen cycle,produces regenerated nitrate in the euphotic zone and emits N_(2)O,a potent greenhouse gas as a by-product.The regulatory mechanisms of nitrification in the Southern Ocean,which is a critical region for CO_(2)sequestration and radiative benefits,remain poorly understood.Here,we investigated the in situ and dark nitrification rates in the upper 500 m and conducted substrate kinetics experiments across the Indian Sector in the Cosmonaut and Cooperation seas in the late austral summer.Our findings indicate that light inhibition of nitrification decreases exponentially with depth,exhibiting a light threshold of 0.53%photosynthetically active radiation.A positive relationship between dark nitrification and apparent oxygen utilization suggests a dependence on substrate availability from primary production.Importantly,an increased NH_(4)^(+) supply can act as a buffer against photo-inhibitory damage.Globally,substrate affinity(α)increases with depth and transitions from light to dark,decreases with increasing ambient NH_(4)^(+)and exhibits a latitudinal distribution,reflecting substrate utilization strategies.We also reveal that upwelling in Circumpolar Deep Water(CDW)stimulates nitrification through the introduction of potentially higher iron and deep diverse nitrifying microorganisms with higherα.We conclude that although light is the primary limiting factor for nitrification in summer,coupling between substrate availability and CDW upwelling can overcome this limitation,thereby alleviating photoinhibition by up to 45%±5.3%.

New insights into the deposition of natural gas hydrate on pipeline surfaces:A molecular dynamics simulation study

Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent NGH blockages.Previous studies suggested the water film can greatly increase hydrate adhesion in gas-dominant system.Herein,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion surfaces.Specifically,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film exists.As water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate deposition.While absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fe<Fe_(2)O_(3)<FeO<Fe_(3)O_(4)).This is because the detachment of deposited hydrate prefers to occur at soft region of liquid layer,the process of which becomes harder as liquid layer vanishes.As a result,contrary to gas-dominant system,the water film plays the weakening roles on hydrate adhesion in water-dominant system.Overall,our results can help to better understand the hydrate deposition mechanisms on Fe and its corrosion surfaces and suggest hydrate deposition can be adjusted by changing water affinities on pipeline surfaces.

Detection of Human Pharmaceuticals in the Surface Water of East Fork Stones River

Pharmaceuticals have been detected nationwide in different environmental matrices including wastewater effluents and surface water. In recent studies, pharmaceuticals have also been found in aquatic plants, fish tissues and plasma of shark bulls. Pharmaceuticals that were detected as indicated in published literature, included steroids, prescription drugs such as antibiotics, anti-depressants, anti-inflammatory drugs, hormones and over the counter (OTC) drugs. We conducted a monitoring study to detect the presence of pharmaceuticals in East fork of the Stones River located in Rutherford County in Middle Tennessee. East Fork Stones River is a six (6) order river that drains a large portion of Rutherford County including Murfreesboro, Tennessee. Grab water samples were collected from Stones River for three seasons: (summer and fall of 2014 and 2015 and winter of 2015 and 2016) each year. Water quality parameters were also determined in situ using Eureka Water ProbesTM multi-parameter sondes. Water samples were analyzed for the presence of pharmaceutical compounds using GC-MS. Chemical Abstract Service Registry Numbers (CASRN or CAS) for detected pharmaceuticals were identified. Pharmaceuticals detected included those used for treatment of chronic alcoholism (Disulfiram: CAS # 97-77-8), a compound (Thiazolidine: CAS # 504-78-9) in the drug Thiazolidinedione which is used for the treatment of type II diabetes, a compound associated with the prevention of anti-inflammatory conditions (Methyl palmitate: CAS # 112-39-0), and emollient in skincare (Undecane: CAS # 1120-21-4). While the quantitative concentrations of these drugs were not determined in this study, their qualitative presence in surface water is noteworthy.

Combination Features,Paleobiogeographic Affinity and Mass Extinction of the Latest Ordovician(Hirnantian) Rugosan Fauna from Northern Guizhou,China

The rugosan fauna from the Guanyinqiao Bed （latest Ordovician, Hirnantian） of northern Guizhou, China is known to belong to the cold or cool-water type corals. The components of the fauna are solitary corals only, and corallite septa are generally strongly dilated, especially the streptelasmatid corals are dominant comprising 98% of the whole fauna. The Guanyinqiao Bed is rich in rugosans of 18 genera, which are streptelasnmtid Streptelasma （=Helicelasma）, Brachyelasma, Amplexobrachyelasma, Salvadorea, Grewingkia, Borelasma, CrassUasma, Leolasma, KenophyUum, UUernelasma, Paramplexoides, Siphonolasma, Pycnactoides, Dalmanophyllum, Bodophyllum, Axiphoria, Lambeophyllum and cystiphyllid Sinkiangolasma. Although this fauna was fairly abundant in a confined area （northern-northeastern Guizhou, southern Sichuan） during the Hirnantian age, the rugosan mass extinction （generic extinction rate 81%） happened at the end of the Hirnantian Stage. It is conduded that the mass extinction is related to the ending of maximum glaciation and ice cap melting in Gondwana in the southern hemisphere in the latest Hirnantian, resulting in rapid global sea-level rise in the earliest Silurian. In the Upper Yangtze Basin, the sea bottom environments were replaced by anoxic and warmer water during that time, so that the cool-water type rugosan became extinct. The present paper attempts to revise some already described rugose coral genera and species （He, 1978, 1985） and to supplement a few new forms from the Guanyinqiao Bed. Fourteen species of 12 genera are re-described and illustrated, of which one species- Grewingkia latifossulata is new. As a whole, the rugosan fauna of the Guanyinqiao Bed may be correlated with those contemporaneous of North Europe, Estonia and North America, indicating a dose biogeographic affinity to North Europe.

An Assessment of Air and Water Pollution Accrued from Stone Quarrying in Mukono District, Central Uganda

The unquenchable demand for rock materials has attracted many companies within the building and construction sector to invest in stone quarrying. However, this has brought about environmental impacts with health threats to people. There is a paucity of information about the magnitude of pollution on air and water and how it varies with quarry sites. This study, therefore, investigated the physical impacts of quarrying on air and water and explored the in-situ mitigations to undesirable effects due to stone quarrying. Four active quarry sites were identified. Field measurements of dust (particulate matter) were conducted within the four quarry sites and in the nearby community. Water samples were collected from quarry pits and nearby shallow wells for laboratory analysis of water quality. Statistical Analysis of Variance (ANOVA) was used to test for differences in pollution across the four studied sites. Results revealed that, amidst the use of wet crushing and water sprinkling on bare surfaces, dust emission was higher than the recommended permissible standards levels with a significant variation across the quarry sites with ANOVA (P-value = 0.003) for PM 2.5 and (P-value = 0.04366) for PM 10. Water pollution was mainly contributed by the non-permissive levels of nitrates, chromium, and pH. Polluted air and water are associated with sparking off health threats to the users in the community. In conclusion, quarry companies should strengthen the already existing mitigation of dust suppression. The study recommends additional measures such as treating quarry pit water before discharging to the open environment to enhance environmental protection against the accumulating undesirable quarry impacts.

Water-affinity of Perlite Products and Its Anti-water Mechanism after Being Modified

The structure modification and its mechanism have been studied when perlite products changed from water-affinity state to anti-water state. The structure of fused perlite and its surface physicochemical properties have also been studied. The modification of perlite products has provided the products with anti-water property, which not only enhanced the quality of thermal insulating function, reduced the lost of heat energy, but also made the products water-proof These modified perlite products are used as ideal thermal insulating layers for the thermodynamic equipment and heat transporting conducts.

Molecular Simulations of Water Transport Resistance in Polyamide RO Membranes: Interfacial and Interior Contributions

Understanding the transport resistance of water molecules in polyamide(PA)reverse osmosis(RO)membranes at the molecular level is of great importance in guiding the design,preparation,and applications of these membranes.In this work,we use molecular simulation to calculate the total transport resistance by dividing it into two contributions:the interior part and the interfacial part.The interior resistance is dependent on the thickness of the PA layer,while the interfacial resistance is not.Simulation based on the 5 nm PA layer reveals that interfacial resistance is the dominating contribution(>62%)to the total resistance.However,for real-world RO membranes with a 200 nm PA layer,interfacial resistance plays a minor role,with a contribution below 10%.This implies that there is a risk of inaccuracy when using the typical method to estimate the transport resistance of RO membranes,as this method involves simply multiplying the total transport resistance of the simulated value based on a membrane with a 5 nm PA layer.Furthermore,both the interfacial resistance and the interior resistance are dependent on the chemistry of the PA layer.Our simulation reveals that decreasing the number of residual carboxyl groups in the PA layer leads to decreased interior resistance;therefore,the water permeability can be improved at no cost of ion rejection,which is in excellent agreement with the experimental results.

Investigations of Physical and Chemical Characteristics of Masonry Stones and Bricks during Building Cleaning： Part 1. Physical Testing

This series of study focused on analysing and assessing the changes of the physical and chemical characteristics of the surfaces of the masonrystones and bricks during the sandblasting cleaning process by conducting various physical and chemical tests. Seven masonry stones and bricks were adopted, including yellow sandstone, red sandstone, limestone, marble, granite, white clay brick and yellow clay brick. The physical testing included evaluating the cleaning degree, determining the Vickers hardness, and detecting the water absorption. Using a digital imaging analysis method, the greyscale and cleanness were introduced to quantitatively assess the effectiveness of masonry building cleaning and confirmed to be useful and appropriate. The cleanness analysis, together with the hardness and water absorption tests showed that a masonry stone or a brick with a higher cleaning degree corresponded to a brighter and harder stone surface. In general, the physical properties were found to vary largely during the building cleaning.

Evaluation of Preservation Effect by Aquo-Siloxane Method towards Water Permeation and Material Diffusion into Porous Rocks

Various kinds of heritages, such as architectures, statues, grave posts and towers, are made by stone, and they are facing the crisis of weathering. Therefore, it is necessary to give appropriate treatments to keep them in good conditions. Kyushu Research Institute for Cultural Properties Inc. and Kumamoto University introduced a new method, Aquo-Siloxane Method, in order to protect the stone heritages. In this study, preservation effect by Aquo-Siloxane method towards water permeation and material diffusion was verified. Here one-dimensional permeation and diffusion tests were conducted, and the intrinsic permeability and diffusion coefficient of rock samples with and without Aquo-Siloxane treatments were evaluated. As rock samples, 3 types of sandstones and concrete were applied. It was found that the permeability decreased to less than 1/10 to 1/100 of without Aquo-Siloxane treatment, and that the effect gradually developed during more than one year. One-dimensional diffusion tests were also conducted, and the diffusion process in rock samples are visualized by X-ray CT scanner system. It was confirmed internal structures of samples are clearly visualized, and that the diffusion process was also visualized as X-ray CT images. In order to extract the necessary information due to diffusion, image subtraction method was applied to image data. Then, by comparing obtained CT image data and numerical solutions, diffusion coefficients of rock samples with and without Aquo-Siloxane treatments were evaluated. As a result, diffusion coefficients also became smaller by applying Aquo-Siloxane treatments. It is revealed that material movement due to diffusion was also efficiently suppressed by applying Aquo-Siloxane method. Finally, Aquo-Siloxane method was applied to a stone heritage. It was found that no more chippings and cracks were observed and that the heritage has been kept in good condition for at least four years.

Interpretation of Peitai Real Scene by Tang Yin in the Ming Dynasty

Peitai Real Scene clearly shows us the gorgeous image of Xu-style gardens in the Ming Dynasty,and discloses the achievement of ancient Xu-style gardens,which is of great significance for studying Xu-style gardens.From the perspective of spatial processing,plant landscaping,architectural style,stone and water layout,this paper brought us back to the ancient glory of Peitai through analyzing this painting,which was extremely valuable for the research on Xu-style gardens.

Characterization of some Egyptian serpentinites used as ornamental stones

Egypt is characterized by wide occurrence of serpentinites, particularly in the central and southern parts of Eastern Desert. There are several cooperate factors that affect the serpentinites used as ornamental stones. These factors involve mineralogical characteristics (including mineral composition and microstructure parameter), physical properties and mechanical properties. Antigorite is an essential serpentinite mineral, with a minor amount of chrysotile. Talc, carbonates (magnesite and dolomite) and tremolite are the main associated minerals. Quality and quantity of associated minerals such as talc and carbonates (dolomite and magnesite) affect the properties of serpentinites used as ornamental stones. Carbonates are resistant to weathering but suffer from acidic cleaning agents in interior use, whereas serpentinites with a high content of talc used on external faces undergo an increase in volume and a consequent rapid degradation. Studied serpentinites are characterized by relatively small grain size with foliated texture, low water absorption, low porosity, and high abrasion resistance. In the samples studied the uniaxial compressive strength (UCS) varies between 89 and 189 MPa, with an average of 152 MPa. According to the classification of Bell (1992), sample No. B8 is very high in strength while the rest high in strength.

基于能量的振冲碎石桩加密效果评价方法

采用常规检测手段进行处理地基的工后质检存在时间滞后与空间局部的问题,不能及时反映处理地基的整体加固效果。提出了一种基于能量的碎石桩复合地基桩周土振动加密效果评价方法,为实现桩周土加密效果的准实时评价提供参考。首先,根据地基弹性波传播理论建立振冲施工过程中桩周土吸收波动能量的计算方法,通过不排水动三轴试验建立典型饱和粉砂土基于吸收能量的超静孔压模型,为进一步根据固结理论预测处理后复合地基桩周土密实度提供依据;其次,依托某工程水电站深厚坝基碎石桩处理工程实例,采用桩周土超静孔压峰值和处理后孔隙比两个关键物理量对方法进行了检验,发现与施工现场实测超静孔压和工后质检得到的孔隙比相比,方法的预测精度达到90%左右,说明基于能量的振冲碎石桩加密效果评价方法具有可行性。

石漠化地区土壤界面水氮耦合研究进展

为探讨石漠化地区土壤界面下的水氮耦合影响因素,本文从石漠化程度、地形异质性、植被恢复措施和土地利用4个方面进行综述,总结出土壤水分和氮素的迁移规律。(1)轻度石漠地区含水量和土壤氮含量较高,导致植物内养分运输快,水氮耦合效果最佳;其次是重度石漠地区;中度石漠地区通常是耕地聚集地,其土壤水氮含量较低,水氮耦合效果也最差。(2)随着海拔的降低,土壤水氮耦合效应增强,但这种效应随土壤深度的增加而减弱;不论是在高原的山地、峡谷、盆地还是洼地,石漠化地区的土壤水分和养分的流失都十分严重;不同植被恢复类型和恢复年限对当地的土壤水及氮素均有影响。(3)植树造林显著提高石漠化土壤的含水量和全氮含量;退耕还林不仅提升土壤肥力和环境质量,还有助于土壤氮库恢复和碳氮平衡维持;封山育林能在一定程度上改善土壤中的氮含量。(4)不同的耕地利用类型和作物选用都会对水氮耦合产生影响;园地通过减少翻耕次数,导致土壤紧实化,从而提高水土保持效果。根据以上研究,今后可针对综合治理策略、生态恢复与水资源综合管理策略、高效植被恢复策略、优化土地管理和利用策略等方面开展研究。

石墨尾矿制备免烧仿石砖工艺与性能研究

目的:研究石墨尾矿制备仿石砖的工艺和性能。方法:通过扫描电子显微镜和力学性能测试等手段对制备的免烧仿石砖进行了表征和评估。结果:研究表明,采用压制成型法利用石墨尾矿制备免烧砖,最佳的石墨尾矿掺混比为50%,陈化时间为21 d,此时免烧砖抗压强度35.53 MPa,吸水率为4.22%,均达到产品要求的标准。结论:通过SEM观察,制备的仿石砖表面平整,无明显的孔隙和裂缝。力学性能测试表明,仿石砖具有较好的抗压强度和耐磨性。意义:利用石墨尾矿制备免烧砖在技术上是可行的,对环境保护和资源回收具有重要意义。

微污染湖泊水体植物-微生物协同修复技术

针对雨水溢流引起的水体微污染的修复,本研究建立了室内微模型模拟雨水溢流污染水体,分别采用投加复合脱氮菌剂、复合脱氮菌剂+镁改性麦饭石,以及复合脱氮菌剂+生态颗粒的方法进行处理,探究不同处理方式对水质、沉水植物苦草及底泥微生物菌群的影响。研究发现,菌剂的投加能够加速微污染水体的修复,同时投加镁改性麦饭石及生态颗粒,能够提升水体氨氮(NH_(4)^(+)-N)、总氮(TN)和化学需氧量(COD)的去除率,并促进苦草生长,其中镁改性麦饭石对苦草与微生物的耦合脱氮促生效果最优。复合脱氮菌剂单独投加,或同时投加镁改性麦饭石或生态颗粒,对底泥细菌群落α多样性影响均不显著。FAPROTAX功能预测表明,Anaerolineaceae等异养硝化-好氧反硝化细菌是苦草与微生物耦合脱氮的主导底泥微生物,镁改性麦饭石及生态颗粒有利于底泥菌群向微生物脱氮功能菌群结构演变,通过植物和微生物协同作用,两处理分别增加苦草叶长26.5%、11.8%,增加根长45.2%、35.5%。

机制砂全再生粗骨料混凝土的力学性能

为探究骨料类型、水灰比与石粉含量对机制砂全再生粗骨料混凝土力学性能的影响,制备了不同石粉质量分数(5%、10%和15%)和不同水灰比(0.50、0.37和0.32)的全再生骨料混凝土试件.以72个立方体试件用于抗压强度试验,72个圆柱体试件用于弹性模量试验.结果表明,合理的石粉含量能有效提高再生骨料混凝土的力学性能,但在不同的水灰比下,最佳石粉含量存在差异;当水灰比和石粉含量双因素交互作用时,水灰比为0.32、石粉质量分数为15%的再生混凝土力学性能达到最优.构建了机制砂再生粗骨料混凝土抗压强度、弹性模量与水灰比、石粉含量的关系模型,计算结果的标准差与离散系数均不超过5%,模型精度良好.研究成果可为提高再生骨料混凝土力学性能及其工程应用提供理论依据.

生态砾石床+碎石湿地在城市劣五类水体治理中的应用

为解决北方寒冷地区城市劣Ⅴ类河道的问题,采用“生态砾石床+碎石湿地系统”的组合工艺,将来水引入湿地进行净化。结果表明:该工艺对北方城市劣V类水体处理效果明显,系统具有较强的耐冲击能力,可降低冬季气温对湿地运行的影响。原水COD≤80 mg/L、NH_(3)-N≤3.0 mg/L、TP≤0.6mg/L时,该工艺系统对COD、NH_(3)-N、TP的平均去除率分别可达59.54%、60.62%和33.42%,出水主要指标满足《地表水环境质量标准》(GB 3838-2002)Ⅴ类水体限值。运行后每年削减COD排放量为1204.50 t,NH3-N排放量为40.15 t,TP排放量为8.03吨,明显改善了河道的生态环境。

抚州市青石建筑表现特征及其材料内在影响因素

江西省抚州市具有丰富的明清历史建筑,其中较多采用一种青石为建筑构件。实地调研得到抚州青石在当地传统建筑中的使用功能和主要部位,通过对抚州市不同地区的青石样品进行化学组成、物相组成、微观形貌及主要物理性能分析,并结合抚州市地理特点,解释了抚州青石的主要劣化机制,为未来抚州市相关的古建筑修复提供理论参考。研究表明:抚州青石主要由架状硅酸盐类矿物组成,其微观结构较致密且力学性能较好,因此具有坚固耐久的特点。抚州青石的主要裂化机制可能是物理损伤及化学侵蚀,其长期暴露在室外会出现局部变色、孔洞甚至剥落等破坏现象,因此在传统建筑的保护中值得注意和采取相应措施。

结石患者腹腔镜切除术后水胶体敷料的应用及对伤口愈合的影响

目的:研究结石患者腹腔镜切除术后水胶体敷料的应用及对患者伤口愈合的影响。方法:选择2020年2月—2022年9月平顶山市第一人民医院收治的129例结石病患者作为研究对象,按照随机数表法分为观察组62例与对照组67例。两组患者均使用腹腔镜微创技术治疗结石病。观察组患者术后早期采用水胶体敷料对切口进行换药护理,对照组患者采用传统敷料对切口进行换药护理。对比两组患者使用敷料后的效果、换药情况,并且对两组患者进行创面评估及疼痛感情况的调查。结果:治疗后,观察组出现红肿、脓性分泌物、肉芽症状明显低于对照组;愈合时间、感觉舒适度明显优于对照组,差异均有统计学意义(χ^(2)=29.804、5.291、49.848;t=11.086;χ^(2)=103.802,P<0.05);观察组1度、2度痂皮瘢痕明显低于对照组,换药时卷边次数低于对照组,差异均有统计学意义(χ^(2)=102.749、19.357,P<0.05);观察组平均沐浴次数明显高于对照组,平均换药次数明显低于对照组,差异均有统计学意义(t=17.860、10.368,P<0.05);观察组患者在治疗后创面评估及疼痛感评分上均优于对照组,差异均有统计学意义(χ^(2)=4.813、13.750、13.929、8.574,11.301、4.897、6.850,P<0.05)。结论:结石患者在进行腹腔镜切除术后使用水胶体敷料相较于传统敷料对患者伤口愈合效果明显改善,是一种安全有效的治疗方法。