High Degree Of Deterioration Research Articles

3D bioprinting of an in vitro hepatoma microenvironment model: Establishment, evaluation, and anticancer drug testing

Tumor behavior, including its response to treatments, is influenced by interactions between mesenchymal and malignant cells, as well as their spatial arrangement. To study tumor biology and evaluate anticancer drugs, accurate 3D tumor models are essential. Here, we developed an in vitro biomimetic hepatoma microenvironment model by combining an extracellular matrix (3DM-7721). Initially, the internal grid structure, composed of 10/6 % GelMA/gelatin loaded with SMMC-7721 cells, was printed using 3D bioprinting. The external component consisted of fibroblasts and human umbilical vein endothelial cells loaded with 10/3 % GelMA/gelatin. A control model (3DP-7721) lacked external cell loading. GelMA/gelatin hydrogels provided robust structural support and biocompatibility. The SMMC-7721 cells in the 3DM-7721 model exhibit superior tumor-associated gene expression and proliferation characteristics when compared to the 3DP-7721 model. Furthermore, the 3DM-7721 type exhibited increased resistance to anticancer agents. SMMC-7721 cells in the 3DM-7721 model exhibit significant tumorigenicity in nude mice. The 3DM-7721 model group showed pathological characteristics of malignant tumors, with a high degree of deterioration, and a significant positive correlation between malignant tumor-related gene pathways. This high-fidelity 3DM-7721 tumor microenvironment model is invaluable for studying tumor progression, devising effective treatment strategies, and discovering drugs. Statement of significance1.A hepatoma microenvironment model (3DM-7721) incorporating an extracellular matrix that is designed to establish solid tumor models in vitro.2.This model contains a 3D-printed internal tumor component of liver cancer cells loaded with 10/6 % gelatin methacrylate (GelMA)/gelatin (the 3DP-7721 model) and an external extracellular-matrix component of fibroblasts and human umbilical vein endothelial cells loaded with 10/3 % GelMA/gelatin.3.The 3DM-7721 model outperforms the 3DP-7721 model in terms of the SMMC-7721 cell proliferation characteristics and tumorigenicity, tumor-related gene expression, anticancer drug resistance, and malignant tumor characteristics.

ANALISIS UMUR SIMPAN GULAI AYAM NANAS KEMASAN KALENG BERBASIS PROYEK IMPLEMENTASI KURIKULUM MERDEKA (IKM)

IKM implements project-based learning that supports 21st-century skills, namely character development according to the profile of Pancasila students, one of which is by utilizing the science laboratory as a place for activities in research and education. Project-based learning can be linked by students to the regional potential of Lahat Regency, South Sumatra Province, one of which is Pineapple Chicken Curry which is food made from free-range chicken or other chicken meat and combined with pineapple and seasoned coconut milk sauce. Along with the times, pineapple chicken curry has now been innovated in cans. The purpose was to analyze canned pineapple chicken curry in the application of IKM project learning through the Accelerated Shelf-Life Testing (ASLT) method. Analysis of the expiration date of canned chicken curry if it is carried out in a curriculum realization project. It can be seen in higher storage temperature pineapple chicken, a shorter shelf life product. The Arrhenius approach yields rocker samples with a shelf life of 0.44 months, 0.49 months, and 0.46-month temperatures at 25°C, 35°C, and 45°C. Higher storage temperature, higher degree of deterioration (k)

Short-term efficacy of cholecystectomy plus bile duct T-tube drainage or choledochojejunostomy in the treatment of gallbladder cancer and its effects on median survival time and postoperative complications.

To explore the short-term efficacy of cholecystectomy plus bile duct T-tube drainage or choledochojejunostomy (CJ) in the treatment of gallbladder cancer (GC) and its effects on the median survival time and postoperative complications. The clinical data of 121 patients who underwent laparoscopic cholecystectomy (LC) in department of hepatobiliary surgery of the hospital from January 2018 to December 2018 were retrospectively analyzed. According to the adjuvant treatment methods, the patients were divided into 2 groups: the control group (n = 61, LC + bile duct T-tube drainage) and experimental group (n = 60, LC + CJ). The perioperative indicators, short-term efficacy, median survival time, postoperative complications and immune stress response were compared between the 2 groups of patients before and after propensity score matching. The surgical time, postoperative anal first exhaust time, and intraoperative blood loss in the experimental group were no different from those in the control group (P > .05), but the hospital stay was shorter than that in the control group (P < .05). There was no difference in the effective rate of treatment and median survival time between the 2 groups (P > .05). The total incidence rate of complications in the experimental group at 14 days after surgery was lower than that in the control group (P < .05). Day 3 after surgery, the levels of immunoglobulin M (IgM) and immunoglobulin G (IgG) of the experimental group were higher than those of the control group (P < .05), while the level of C-reactive protein (CRP) was lower than that of the control group (P < .05). Compared with bile duct T-tube drainage, LC + CJ in the treatment of GC can better shorten the postoperative hospital stay and reduce the postoperative complications and immune stress response, but and the median survival time of the 2 is similar, which can be promoted in clinical practice.

ASI-DBNet: An Adaptive Sparse Interactive ResNet-Vision Transformer Dual-Branch Network for the Grading of Brain Cancer Histopathological Images.

Brain cancer is the deadliest cancer that occurs in the brain and central nervous system, and rapid and precise grading is essential to reduce patient suffering and improve survival. Traditional convolutional neural network (CNN)-based computer-aided diagnosis algorithms cannot fully utilize the global information of pathology images, and the recently popular vision transformer (ViT) model does not focus enough on the local details of pathology images, both of which lead to a lack of precision in the focus of the model and a lack of accuracy in the grading of brain cancer. To solve this problem, we propose an adaptive sparse interaction ResNet-ViT dual-branch network (ASI-DBNet). First, we design the ResNet-ViT parallel structure to simultaneously capture and retain the local and global information of pathology images. Second, we design the adaptive sparse interaction block (ASIB) to interact the ResNet branch with the ViT branch. Furthermore, we introduce the attention mechanism in ASIB to adaptively filter the redundant information from the dual branches during the interaction so that the feature maps delivered during the interaction are more beneficial. Intensive experiments have shown that ASI-DBNet performs best in various baseline and SOTA models, with 95.24% accuracy in four grades. In particular, for brain tumors with a high degree of deterioration (Grade III and Grade IV), the highest diagnostic accuracies achieved by ASI-DBNet are 97.93% and 96.28%, respectively, which is of great clinical significance. Meanwhile, the gradient-weighted class activation map (Grad_cam) and attention rollout visualization mechanisms are utilized to visualize the working logic behind the model, and the resulting feature maps highlight the important distinguishing features related to the diagnosis. Therefore, the interpretability and confidence of the model are improved, which is of great value for the clinical diagnosis of brain cancer.

Influence of a Pre-consolidation Treatment on the Desalination Effectiveness of a Highly Deteriorated Granite Façade of Medieval Age

ABSTRACT In this study, the pre-consolidation of the granite used in the north façade of St. Martin’s Cathedral in Ourense, of Romanesque style (S. XII–XIII), and its influence on the effectiveness of a subsequent desalination treatment using poultices of different composition is presented. The need for both treatments lay in the high degree of deterioration of the granite of the façade, which suffers an intense sand disaggregation associated with salt crystallization. The effectiveness and harmful effects of the pre-consolidation using a conventional TEOS (Estel 1000) and a nanoconsolidant based on silicon oligomers (UCAD-2o), initially under laboratory conditions and later on site, were evaluated. In situ desalination was performed applying different types of poultices chosen taking into account the pore distribution of the pre-treated granite. The obtained results, both in the laboratory and on-site, show that the pre-treatment of the deteriorated granite with UCAD-2o restores the necessary cohesion to the rock to be subsequently desalinated, increasing—compared to the other consolidant—the efficiency of desalination through the higher reduction in the granite’s pore volume with capillary access diameter. This research contributes new data to improve the most serious conservation problems that affect granitic monuments affected by soluble salts, when the intense sand disaggregation process complicates the desalination due to the risk of loss of surface material.

Resistance of blended alkali-activated fly ash-OPC mortar to mild-concentration sulfuric and acetic acid attack.

The traditional cementitious product is prone to suffer from a high degree of deterioration in the case of exposure to acid solutions because of the decomposition of the binder network. However, the degradation of concrete structures in service by mild concentrations of acid under conditions involving sewage, industrial waters, and acid rain is more common and results in a significant environmental problem. The utilization of alkali-activated materials has been seen to potentially offer an attractive option with regard to acceptable durability and a low carbon footprint. With the aid of visual observation, mass loss, compressive strength tests, X-ray diffraction, Fourier transform infrared spectroscopy, and field-emission scanning electron microscopy with energy-dispersive X-ray spectroscopy, the acid resistance of alkali-activated fly ash mortars in which the precursor was partially replaced (0-30% by mass proportion) with ordinary Portland cement (OPC) was evaluated after 180 days of exposure to mild-concentration sulfuric and acetic solutions (pH = 3). A conventional cement mortar (100% OPC) was used as a reference group. The results demonstrate that the addition of OPC into the alkali-activated system causes a significant increase in compressive strength (around 16.08-36.61%) while showing an opposite influence on durability after acid attack. Based on a linear mean value and nonlinear artificial neural network model simulation, the mass losses of the specimens were evaluated, and the alkali-activated pure-fly ash mortar demonstrated the lowest value (i.e., a maximum of 5.61%) together with the best behavior in the aspect of discreteness at 180 days. The results from microstructure analysis show that the coexistence of the N-A-S-H and C-S-H networks in the blend system occurred by both OPC hydration and FA. However, the formation of the gypsum deposition within the fly ash-OPC blend systems at sulfuric acid was found to impose internal disintegrating stresses, causing a significant area of delamination and cracks. In addition, alkali metal ion leaching, dealumination, as well as the disappearance of some crystalline phases occurred in specimens immersed in both types of acids.

Development of alkali-activated composites from calcined iron-rich laterite soil

An experimental investigation was carried out to investigate the feasibility of using calcined iron-rich aluminosilicate (i.e. laterite soil) as a precursor for making alkali-activated mortars (AAMs). Laterite soil was calcined at a temperature of 600 °C and activated with an alkali solution in order to produce the AAMs. The developed AAMs were cured at 27 °C and 80 °C for 4 h followed by continuous curing at 27 °C until testing. The corresponding mechanical and durability performance of the AAMs were evaluated at 7, 28 and 90 days.The findings from this study showed that the use of initial elevated curing (i.e. at 80 °C) enhanced the performance of the AAMs. AAMs cured at 80 °C exhibited compressive strength and flexural strength up to 32.2 MPa and 12.1 MPa, respectively at 28 days. It was also found out that the mechanical performance of the AAMs can be correlated with the apparent porosity and water absorption. The microstructure evaluation of the AAMs revealed that the binder phases are a mixture of amorphous Na-aluminosilicate and iron silicate binder phases surrounding the sand particles. Similar to the mechanical performance, AAMs cured at 80 °C exhibited better resistance to the acid environment (H2SO4 solution of pH=1) than the ones cured at 27 °C. The higher degree of deterioration in AAMs cured at 27 °C was due to the lower rate of reaction and higher porosity in the AAMs. The properties of the end products showed that calcined laterite is a decent alternative precursor for alkali-activated materials.

ВЛИЯНИЕ КОНСТРУКТИВНЫХ ОСОБЕННОСТЕЙ НА РЕГУЛИРУЮЩУЮ СПОСОБНОСТЬ ИНЖЕКЦИОННЫХ ВОДОВЫПУСКОВ

The high degree of deterioration of hydraulic structures of reclamation systems and a decrease in the efficiency of using reclaimed land required the adoption at the state level of a number of programs The high degree of deterioration of hydraulic structures of reclamation systems and a decrease in the efficiency of using reclaimed land required the adoption at the state level of a number of programs aimed at the development and modernization of the reclamation complex of Russia. Ensuring the water regime on irrigated lands requires the introduction of technological innovations that can ensure the regulation of the water supply of hydraulic structures without involving non-renewable energy sources with maximum savings in water resources. The injection flow controllers considered in the work are able to use the hydraulic energy of the flow and carry out the control process with feedback.With a decrease in water consumption downstream, the regulator changes its capacity, providing the circulation of excess incoming water at the end of the structure. The operation of water outlets is based on the injection process, in which the regulator is a kind of jet pump located under the structure blocking the channel or under the dam of a small pond. The energy of the flow passing through the pipe from the upper stream is used to inject excess water coming from the reverse wave current through the diverting channel. The results of theoretical studies, physical and numerical modeling of injection water outlets with various forms of execution of the flow part are presented. Particular attention is paid to the execution of the output section of the structure – the diffuser and the prismatic section in front of it – the mixing chamber. The values of the hydraulic resistance coefficients of pyramidal diffusers with a high degree of expansion were studied and obtained for the first time. To prevent flow failure, the diffusers are equipped with shortened separate walls. The processing of the experiment data is carried out in accordance with international standards. When numerically modeling the flow in the regulator, the data of the physical experiment are used as the initial and boundary conditions. There is given a comparison of the fl ow rate of the studied regulators, the values of the parameters necessary for performing the hydraulic calculation are determined.

Technical and Economic Assessment of Local Power Supply Systems for Agro-Industrial Production in the Digital Economy

Energy and energy supply development determines the rate of production intensification, including agricultural production. The current state of rural power supply is characterized by a high degree of deterioration of electrical equipment, long distance overhead power lines, low reliability of low-voltage electrical networks, and a higher accident rate. With an aim of ensuring food security and export orientation of the industry for the next 5 years, it is necessary to implement a set of measures to improve the efficiency of energy supply to agricultural production. This task will be hampered by a constant rise in prices and tariffs for energy resources. Thus, over the last 20 years, energy costs have increased from 3-5 % to 30-40 % in agricultural production. The specific capital investment (per 1 kW of power) and the cost of 1 kWh of electricity were reported to depend on a type of local energy source and its capacity. The paper proposes a method for marking out the economic boundaries of the effective use of local power supply arrangements to replace a standard central station. A power gen-set supplying energy to an agricultural holding is capable of operating in two modes subsequent upon utility (central station) electricity – autonomous and parallel. The authors compared the cost of electrical and thermal energy produced by the power gen-set and tariffs for these types of energy. Calculations have shown that it is advisable for an agricultural holding to have a local power supply system being a power gen-set based on gas engine-generators.

Contextual housing environment and mental health of asylum seekers – a multi-level analysis

Abstract Background Housing is an important determinant of health among asylum seekers and refugees (ASR). Little is known about the effects of contextual housing environment. We used state-wide reliable and valid data to examine these effects on ASR mental health. Methods We drew a balanced random sample of 58 shared refugee accommodation centers (SRA) from 1938 centres with 70,634 ASR in Germany's 3rd largest federal state. We measured depression (PHQ2) and anxiety (GAD2) using established instruments in nine languages. We assessed physical housing environment with a validated multi-dimensional Small-area Housing Environment Deterioration index (SHED). Linking survey- and SHED-data to GIS- and secondary data sources on accommodation size and remoteness, district urbanity and deprivation, we used multi-level logistic regression to calculate exposure effects and 95 % confidence intervals (CI), while adjusting for age, sex, relocations and chronic illness. Results Of 412 ASR living in 58 SRA, 45.0% of inhabitants and 35.7% of SRA were rated as having a high/very high degree of deterioration. The odds for reporting symptoms of generalized anxiety increased for the highest degree of deterioration (1.30; 0.37-4.55), large accommodation size (1.01; 1.00-1.03), remoteness (1.63; 0.61 - 4.36), district urbanity (1.67; 0.66-4.20) and deprivation (1.33; 0.60-2.92). The odds of depression symptoms increased in SRA with highest deterioration (1.98; 0.74-5.33) and accommodation remoteness (1.10; 0.48-2.52), decreased in SRA with district urbanity (0.63; 0.31-1.28) and district deprivation (0.66; 0.36-1.23) but not large accommodation size (1.00; 0.99-1.02). Conclusions Almost half of ASR are living in SRA with high/very high degree of deterioration. There is a general tendency of higher odds for mental illness symptoms conditional on housing environment. Future analyses with sample size calculations are needed to better understand these health associations for shared refugee accommodation. Key messages We described contextual housing environment, i.e. degree of deterioration, accommodation size, remoteness, urbanity and deprivation, of a balanced random sample of 58 shared refugee accommodations. In multi-level logistic regression, contextual housing environment tends to be associated with higher odds for reporting symptoms of mental illness.

Acute colonic pseudo-obstruction after cesarean section and gastrointestinal symptoms⋆

ObjectiveTo investigate whether women who developed acute colonic pseudo-obstruction (ACPO) after cesarean section have a higher degree of gastro-intestinal symptoms than women who did not develop ACPO after cesarean section. ACPO is a colonic dilatation without mechanical obstruction, and with an unknown pathophysiology. In younger people it is mostly seen in women after cesarean section. The hypothesis of the present study is that long-term consequences of gastrointestinal symptoms evolve after ACPO, due to the impact on the colon. Study design40 women who developed ACPO after cesarean section (cases) and 80 women, who did not develop ACPO after cesarean section (controls), were asked to participate in the study. The controls were matched based on time of cesarean section (± 14 days), age (±5 years), singleton or twin, parity, cesarean section grade, and ASA-group. Baseline characteristics and information regarding the cesarean section were collected from medical records. An electronic collection of surveys was distributed to the participants, including the following: Irritable Bowel Syndrome - Severity Scoring System (IBS-SSS), Rome IV, Gastrointestinal Symptoms Rating Scale (GSRS), Visceral Sensitivity Index (VSI), Patient Health Questionnaire 15 (PHQ15), The MOS 36-item Short-Form Health Survey (SF-36), and Hospital Anxiety and Depression Scale (HADS). The score from IBS-SSS after cesarean section was used as the primary outcome. Results25 cases and 37 controls participated in the study. A difference in blood loss was found with a median of 600 mL in cases, compared to 400 mL in controls during cesarean section (p = 0.002). No difference was found between cases and controls in the IBS-SSS score after cesarean section. However, cases yielded a higher difference between IBS-SSS before and after cesarean section, indicating a higher degree of deterioration in gastrointestinal symptoms (p = 0.026). In addition, cases reported a higher degree of pain in everyday life (p = 0.039). No difference was found in the remaining surveys. ConclusionWomen undergoing cesarean section developed mild grade of irritable bowel syndrome. However, gastrointestinal symptoms did not seem to be more prevalent in women who developed ACPO, although women with ACPO had a higher degree of deterioration in gastrointestinal symptoms than controls.

Behaviour and Residual Strength Prediction of Recycled Aggregates Concrete Exposed to Elevated Temperatures

Natural aggregates replaced partially or fully with recycled concrete aggregates (RCA) in preparing concrete has emerged as a sustainable construction technique and investigating the properties of such concrete has already been the focus of number of published studies. However, limited data are available for the case of recycled aggregate concrete (RAC) when it is exposed to extreme conditions like elevated temperatures resulting from accidental fires. In this study emphasis was, therefore, made to investigate residual properties of RAC in terms of compressive and tensile strengths, modulus of elasticity, Poisson’s ratio, and concrete mass loss of RAC subjected to elevated temperatures by conducting a detailed experimental investigation. For this purpose, concrete cylindrical specimens were cast having 0%, 30%, 50%, 70% and 100% RCA. These cylinders were then exposed to elevated temperatures ranging from 250 to 900 °C. Based on the experimental results, Elastic modulus and Poisson’s ratio were found to be significantly influenced for the specimens having percentages of recycled aggregates above 30% and when subjected to temperature elevation of above 500 °C. Overall, behaviour of RAC was more or less similar to natural aggregate concrete with a higher degree of deterioration. Furthermore, a residual strength factor (RSF) was also proposed to predict the residual strengths of RAC exposed to elevated temperatures which can be used effectively to estimate residual strengths of NAC and RAC when exposed to elevated temperatures.

Changes in soil microbial communities at Jinsha earthen site are associated with earthen site deterioration

BackgroundEarthen sites are immobile cultural relics and an important part of cultural heritage with historical, artistic and scientific values. The deterioration of features in earthen sites result in permanent loss of cultural information, causing immeasurable damage to the study of history and culture. Most research on the deterioration of earthen sites has concentrated on physicochemical factors, and information on microbial communities in earthen sites and their relationship with the earthen site deterioration is scarce. We used high-throughput sequencing to analyze bacterial and fungal communities in soils from earthen walls with different degree of deterioration at Jinsha earthen site to characterize the microbial communities and their correlation with environmental factors, and to compare microbial community structures and the relative abundances of individual taxa associated with different degree of deterioration for identifying possible marker taxa.ResultsThe relative abundances of Proteobacteria and Firmicutes were higher and that of Actinobacteria lower with higher degree of deterioration. At the genus level, the relative abundances of Rubrobacter were highest in all sample groups except in the most deteriorated samples where that of Bacteroides was highest. The relative abundance of the yeast genus Candida was highest in the severely deteriorated sample group. The bacterial phylum Bacteroidetes and genus Bacteroides, and fungal class Saccharomycetes that includes Candida sp. were specific for the most deteriorated samples. For both bacteria and fungi, the differences in community composition were associated with differences in EC, moisture, pH, and the concentrations of NH4+, K+, Mg2+, Ca2+ and SO42−.ConclusionThe microbial communities in soil with different degree of deterioration were distinctly different, and deterioration was accompanied with bigger changes in the bacterial than in the fungal community. In addition, the deteriorated soil contained higher concentrations of soluble salts. Potentially, the accumulation of Bacteroides and Candida plays an important role in the deterioration of earthen features. Further work is needed to conclude whether controlling the growth of the bacteria and fungi with high relative abundances in the deteriorated samples can be applied to alleviate deterioration.

Impacto microbiológico y toxicológico del cauce del rio balsas, región tierra caliente de Guerrero

En los últimos quince años se ha registrado un alto grado de deterioro en el río Balsas, México, debido a los asentamientos humanos e industriales. El objetivo de este estudio fue evaluar la condición actual del río y establecer la relación entre los parámetros de la legislación vigente y las pruebas de toxicidad y mutagenicidad. Se determinaron parámetros de campo (color, olor, temperatura, CE, pH, OD), fisicoquímicos (SST, SDT, SSe, DBO5, DQO y GyA, Ntotal, Norg, Ptotal, Porg, ortofosfatos), metales pesados (As, Cd, Cu, Cr, Cr+6, Hg, Ni, Pb, Zn, Al, Fe, Mn), microbiológicos (coliformes fecales) con base en los límites máximos permisibles (LMP) en la NOM-001-ECOL-1996 y en los CE-CCA-001/89, análisis de toxicidad (Vibrio fischeri, Daphnia magna) y mutagenicidad (prueba de Ames con microsomas/Salmonella typhimurium), en época de sequía en nueve estaciones a lo largo de 85km. Los valores para OD, DBO5 y DQO fueron de 2-6, 11-270 y 22-1841mg·l-1, respectivamente. Los metales fueron detectados por debajo de los LMP en todas las estaciones, excepto en la estación 5 (0,002mg·l-1 de Hg) y la 8 (0,13mg·l-1 de Cr+6). Los coliformes fecales rebasaron los LMP en todas las estaciones. Los valores para Vibrio fischeri, Daphnia magna se encuentran en 2-28 y 1-4UT, y para la prueba de Ames entre 5 y 63RM, indicando toxicidad y mutagenicidad desde la estación 3 a la 9. Se registró contaminación alta según la legislación vigente y un riesgo para la salud pública de acuerdo a los parámetros toxicológicos y mutagénicos.

Durability performance of geopolymer cement based on fly ash and calcium aluminate cement in mild concentration acid solutions

The present work evaluates 2-year durability performance of geopolymer cement (GC) mortar derived from a blend of low calcium fly ash and calcium aluminate cement in hydrochloric and sulfuric acid solutions of mild concentration (pH 3). The dry binary blend was activated by a solution of sodium hydroxide and liquid sodium silicate and the GC mortar specimens were cured hydrothermally. At different time intervals of acid attack, the compressive strength and mass loss of specimens were measured and complementary studies on compositional and microstructural changes were performed using X-ray diffractometry, Fourier transform infrared spectroscopy, and scanning electron microscopy with energy dispersive X-ray spectroscopy. The results revealed a superior durability performance for GC mortar especially in hydrochloric acid, compared to Portland and high alumina cement mortars used as reference. In addition, all the three cements showed a considerably higher degree of deterioration in exposure to sulfuric acid than in hydrochloric acid.

IRI Sensitivity to the Influence of Surface Distress on Flexible Pavements

Today, authorities responsible for the operation of highways aim to provide comfort to road users as well as safety while driving. While driving, the most important component that determines comfort for road users is the pavement. The relative effects of various surface distress types in bituminous, hot mixed asphalt pavements on the International Roughness Index (IRI) component—used to evaluate the present performance, and hence the comfort, of pavements—are determined in this study. The presence of only one type of surface distress is very difficult to achieve in practice, especially in regards to pavements where a high degree of deterioration is observed. The presence of different types of surface distress in road pavements, due to similar problems in very close positions and even in nested forms, makes it difficult to assess this issue. The relationships between surface distress and IRI have been modelled to overcome this challenge. To this end, the Multivariate Adaptive Regression Splines (MARS) modelling approach, which is very successful in investigating the relationships between a large number of independent variables and dependent variables, has been used. The sensitivities of the surface distress inputs are evaluated singularly by means of a model with 29 input variables calibrated using the pavement distress data collected in 3295 highway pavement sections. As a result of this analysis, the sensitivity of surface distress inputs collected, as an area, has been determined to have an effect on the increase in IRI. The results are interpreted with the help of figures and tables.

Evaluación de la vulnerabilidad sísmica de 97 edificaciones de la “Comuna Santa Clara de San Millán”, Quito

Ecuador se caracteriza por ser un país multiamenazas frente a desastres naturales, por ello el esfuerzo por mejorar la calidad de las edificaciones debería ser una prioridad. De los trágicos acontecimientos sucedidos en Pedernales en abril de 2016 se han extraído datos importantes provenientes de las edificaciones colapsadas o con alto grado de deterioro, en las que se evidencian tres características en común: 1. Construcciones sin criterios estructurales normados; 2. Ausencia de control profesional durante la construcción; y 3. Falta de previsión de posibles daños estructurales ante la incidencia de un sismo de gran intensidad. Ante el latente riesgo que enfrenta la ciudad de Quito, se presenta una investigación donde se evalúa la vulnerabilidad sísmica en cuanto a la configuración estructural de 97 edificaciones de la Zona 1 de la Comuna Santa Clara de San Millán, ubicada en el sector occidental del Distrito Metropolitano de Quito, conformada en su gran mayoría por construcciones informales, con base en el levantamiento y evaluación de dichas construcciones, para ello se aplica la guía práctica para evaluación sísmica y rehabilitación de estructuras de conformidad con NEC 2015, que determina que el 91,8% de las edificaciones evaluadas poseen alta vulnerabilidad sísmica.

Viral Management as a New Type of Enterprise Management in Coal Industry

The article considers the evolution of the concept of “management”. The Internet analysis of the concept of “viral management” was conducted, the results of which testify to the positive trend, the growing interest in scientific circles, the relevance of the chosen direction for further research and the increasing popularity of the viral management among business leaders. The indices of coal and brown coal extraction in Ukraine and Russia for 2010-2016 are analyzed. Among the problems that exist in the coal industry are the following: mine assets have a high degree of deterioration; the equipment is rather obsolete and does not correspond to the world level; among the existing face equipment, the specific weight of longwall mining equipment, road headers, loading machines, and belt conveyors of the new generation is only several percent. Five steps of introduction of the virus management at the enterprise are identified: opening, development, participation, diffusion, sustainability. The principles of introduction of the viral management in the enterprises of the coal industry are offered. It is established that the main idea of the viral management is to “infect” the organization and, mainly, employees with one or another “virus” in the form of a common idea or goal. It is indicated that the viral management assumes a certain automaticity of changes, internal “obsession” with this or other innovation, involvement of an informal personal factor.

Compressive and Flexural Behaviour of Unstressed Concrete Substructure in Cassava Effluent Contaminated Soils

Concrete research is gradually shifting from the conventional strength-based approach to durability-centred in the past decade. Durability is the measure of the robustness of constructed facilities against deterioration tendencies. The rate of deterioration is affected by the loading condition, and more importantly the physical and chemical nature of the host environments. This paper reports the experimental investigation of unstressed concrete substructure in the natural (uncontaminated) and cassava’s hydrocyanide effluent-polluted soils on the compressive and flexural strengths of buried concrete specimens for a maximum of 84 days. The compressive strengths of the cubes were tested every 7 days until the 84th day, while the beams were only subjected to third-point loading flexural tests at age 84 days. The compressive strength of concrete specimens in the two soil environments increased, though the trend was lower in the polluted soil. The strength reduced by 2.50% to 9.47% between the 7th and 28th days, but steadily between the 28th and 84th days with strength loss of 9.95% (COV = 2.64%). The load-deflection curves were quadratic for the beams in the two geo-environments. The beams in cyanide-polluted soil lost 34.5% of its flexural stiffness, while its loss of load-carrying capacities at the first crack and ultimate failure was 15.8% and 20% respectively. Higher degree of deterioration is certain for loaded concrete substructures in similar conditions. Hence, prior knowledge of soil chemistry is crucial to determining suitable concrete grade and nominal cover for durable substructural elements.

Corrosion Deterioration in Consumer Battery Litter

Recent studies have shown that the annual rates of consumer battery litter on urban pavements can be as high as 215 batteries per hectare of pavement and 0.4 batteries per meter of curb. As littered batteries deteriorate, they release components (Ag, Ba, Cd, Cr, Cu, Hg, Li, Mn, Na, Ni, Pb, Ti, and Zn) that can be significant sources of storm-water contamination. Results of ambient environmental and laboratory-accelerated corrosion studies are presented to quantify the mechanisms that yield chemical deterioration of littered batteries. The analysis concentrates on AA size alkaline and zinc chloride/zinc carbon (ZnCl/ZnC) cells since these are the most commonly littered batteries. Results indicate that littered batteries exposed to ambient well-drained environmental conditions for more than two months will develop surface corrosion over most of their surface but fewer than 10% will be ruptured by corrosion within the first 6 months. This agrees well with field observations. Exposure under poorly drained conditions yields more rapid deterioration but it requires exposure to more aggressive conditions such as those produced by road salts to reproduce the high degree of deterioration observed in some battery litter.