Mesozoic–Cenozoic Uplift/Exhumation History of the Qilian Shan, NE Tibetan Plateau: Constraints From Low-Temperature Thermochronology

The Qilian Shan, which is located along the northeastern margin of the Tibetan Plateau, plays a key role in understanding the dynamics of the outward and upward growth of the plateau. However, when and how tectonic deformation evolved into the geographic pattern which is currently observed in the Qilian Shan are still ambiguous. Here, apatite fission track (AFT) thermochronology and sedimentology were conducted to interpret the low-temperature tectonic deformation/exhumation events in well-dated Late Miocene synorogenic sediment sequences in the Xining Basin, which is adjacent to the southern flank of the Qilian Shan. These new low-temperature thermochronological results suggest that the Qilian Shan experienced four stages of tectonic exhumation during the late Mesozoic–Cenozoic. The Late Cretaceous exhumation events in the Qilian Shan were caused by the diachronous Mesozoic convergence of the Asian Plate and Lhasa Block. In the early Cenozoic (ca. 68–48 Ma), the Qilian Shan quasi-synchronously responded to the Indian–Asian plate collision. Subsequently, the mountain range experienced a two-phase deformation during the Eocene–Early Miocene due to the distal effects of ongoing India–Asia plate convergence. At ca. 8 ± 1 Ma, the Qilian Shan underwent dramatic geomorphological deformation, which marked a change in subsidence along the northeastern margin of the Tibetan Plateau at that time. Our findings suggest that the paleogeographic pattern in the northeastern Tibetan Plateau was affected by the pervasive suture zones in the entire Qilian Shan, in which the pre-Cenozoic and Indian–Asian plate motions reactivated the transpressional faults which strongly modulated the multiperiodic tectonic deformation in northern Tibet during the Cenozoic. These observations provide new evidence for understanding the dynamic mechanisms of the uplift and expansion of the Tibetan Plateau.

Innovative Techniques for Optimization of Far-Field Diverter Materials to Enhance Fracture Geometry in Carbonate Reservoirs

The technique of employing specialized particulates for far-field diversion is well-established during hydraulic fracturing treatments in unconventional formations and is being investigated for use in conventional formations. Far-field diverters (FFD) divert fluid away from the wellbore far into the formation. The injection of FFD at the beginning of the treatment provides an additional stress barrier between the producing interval and adjacent layers by depositing at the layer boundaries where higher leak-off is encountered. The ensuing restriction in height growth maximizes fracture extension within the producing zone, optimizing geometry for increased hydrocarbon production while limiting excess water. Polylactic Acid (PLA) polymer is self-degradable, compatible with reservoir fluids, and has a variety of compositions for different temperature applications. Blending proppant with PLA has been seen to significantly improve the strength of the deposited far-field diverter. Therefore, PLA powder and silica proppant are blended to develop Generation-1 far-field diverter (FFD-Gen1). However, many silica proppants have greater density than PLA, leading to separation during transport which prevents these two components from depositing evenly at the upper fracture boundary. This results in a situation in which excessive downward growth is prevented while upward growth is left unchecked. For this reason, both components need to be simultaneously deposited in order to develop an effective seal. Generation-2 far-field diverter (FFD-Gen2) is developed by replacing silica proppant of FFD-Gen1 with a deformable proppant having a density nearly equal to the polymer, which enables uniform deposition on all adjacent formation boundaries where leakoff is encountered. The deformable characteristic improves the pressure withstanding capacity of the diverter pack. The deposition and degradation behaviors are investigated in the laboratory by performing HTHP filter press and plug stability experiments. Experimental findings suggest that the primary selection criteria for acceptable performance are the material's mechanical properties. This methodology is used to select the appropriate FFD materials to optimize fracture geometry in carbonate reservoirs. Successful applications prevent excessive water production and substantially increase hydrocarbon production as illustrated in a three well case studies.

Dynamics of Multiple Slip and Thermal Radiation on Hydromagnetic Casson Nanofluid Flow over a Nonlinear Porous Stretchable Surface

Aims/ Objectives: This paper examines the dynamics of multiple slip together with thermal radiation effects on the transport of a magnetohydrodynamic Casson nanofluid passing a nonlinear porous stretchable sheet in the existence of viscous dissipation and chemical reaction.Study Design: Cross-sectional study. Methodology: The outlining equations modeling the transport phenomenon are simplified into nonlinear ordinary differential equations via the approach of similarity transformations and subsequently analyzed numerically by shooting techniques alongside Runge-Kutta Fehlberg scheme.Results: The outcomes of decisive parameters affecting the flow, heat, and nanoparticle concentration are graphically deliberated. From the investigation, it is revealed that Brownian motion, viscous dissipation, and thermophoresis parameters augment the thermal boundary layer and propel an upward growth in the temperature profile. Furthermore, the slip factor decelerates the flow and heat dissipation while the fluid movement drags in the existence of the magnetic field. Conclusion: The results obtained in this study compared favourably well with existing related studies in literature under limiting scenarios.

Characterization of the morning transition from downslope to upslope winds and its connection with the nocturnal inversion breakup at the foot of a gentle slope.

<p>Thermally driven winds observed in complex terrain are characterized by a daily cycle dominated by two main phases: a diurnal phase in which winds blow upslope (anabatic), and a nocturnal one in which they revert their direction and blow downslope (katabatic). This alternating pattern also implies two transition phases, following sunrise and sunset respectively. </p><p>Here we study the upslope component of the slope wind with a focus on the morning transition from the katabatic to the anabatic flow based on data from the MATERHORN experiment, performed in Salt Lake Desert (Utah) between Fall 2012 and Spring 2013 (Fernando et al, 2015). </p><p>First of all, a criterion for the selection of purely thermally driven slope wind days is proposed and adopted to select five case studies, taken from both the spring and the autumn periods. Then, the analysis allowed the investigation of the driving mechanisms through the connection with the patterns of erosion of the nocturnal inversion in the valley bed at the foot of the slope under analysis. Three main patterns of erosion of the inversion in the particular topography of a gentle and isolated slope are identified: a) erosion due to upward growth of a convective boundary layer, b) erosion due to descent of the inversion top, and c) erosion due to a mix of the two previous mechanisms. The three patterns are then linked to the initiation of the transition by two different and competing mechanisms: mixing from above (top-down dilution) and surface heating from below. Finally, an analytical model for the description of slope circulation (Zardi and Serafin, 2015) has been used to diagnose the time of the transition.</p><p>Zardi, D. and S. Serafin, 2015: An analytic solution for daily-periodic thermally-driven slope flow. Quart. J. Roy. Meteor. Soc., 141, 1968–1974. </p><p>Fernando, H. J. S., Pardyjak, E. R., Di Sabatino, S., Chow, F. K., De Wekker, S. F. J., Hoch, S. W, Zsedrovits, T., 2015, The MATERHORN: Unraveling the intricacies of mountain weather. <em>Bulletin Of The American Meteorological Society</em>, 96, 1945-1967. </p>

Analysis of the invasion of water lilies (Eichhornia crassipes (Mart) Solms) in the Cointzio dam, Michoacán, Mexico

Objective: to analyze the growth dynamics of the water lily (Eichhornia crassipes)in the Cointzio dam due to the water availability.Design/Methodology/Approach: a monthly series of 45 Sentinel 2 and Landsatsatellite images were used, with which the percentage of invasion of the water lilyin the total area of the reservoir was calculated. The relative coverage of the lilywas analyzed looking for growth patterns over time, as well as the precipitationdata, total reservoir area over time, and water storage data for the 2010-2020period to broaden its context.Results: Three ascending and two descending patterns of the water lily coveragewere identified; a 15-month upward growth pattern with slight inland slope changes; decreasing patterns are associated with decreased water storage. Thelargest lily covers were found in critical storage stages during the 2010-2020period.Study limitations/implications: faced with climate change conditions, the fillingpattern of the dam could change, aggravating problems related to the water supply.Conclusions: containment/mitigation efforts have a reduced effect because the lilyeasily recovers the covered area, growing about 400% between October 2017 andJune 2018, therefore it is necessary to implement a containment strategy using thebiophysical interactions of the basin in conjunction with social, political, economicand governance interactions.

BIOECOLOGICAL BASES OF INTERMEDIATE USE LOGGING IN NUT-PRODUCING AREAS OF CEDAR FORESTS

An increase in the production of scarce pine nuts provides for the creation of a reliable base of walnut harvesting in walnut-producing zones. A significant part of them (10.6 million hectares) does not correspond to the intended purpose and is used irrationally in the absence of documents regulating economic activity. The basis of the base being created can be cedar forest gardens of the near-settlement type, formed by intensive intermediate felling. They should contribute to the formation of the maximum volume of the female generative layer - the basis of the crop - by the age of the highest nut productivity. Bioecological features of the formation of the female generative layer depending on the lighting conditions and the age of the trees are described. It forms on the illuminated part of the crown, closer to the top, and its volume depends on the closeness and age of the trees. Female sexualization is characteristic of shoots of younger orders of branching and younger age. Older shoots and branching orders are characterized by male sexualization. After complete lightening, the female generative layer grows upward, and its volume increases. With moderate lightening, simultaneously with upward growth, branches in the lower part of the fruiting layer are reborn, and its volume changes slightly. The female generative layer is not formed in the middle and lower parts of the trunk after clarification. In clean closed 120-year-old cedar forests, narrow, 70-80% non-fruiting crowns with a highly raised fruiting layer are formed in trees. Its volume is 60-70% less than that of freely growing cedars. Clarification of trees at this age, with a decrease in the recommended fullness to 0.5, is ineffective. The female generative tier will no longer reach the biologically possible potential: in the middle and lower parts of the trunk, the branches of female sexualization are replaced by male and growth shoots. The upward expansion of the female generative layer will provide only a limited reproductive effect. Cutting operations 40 years earlier, i.e. at 80 years old, will increase the potential volume of the fruiting layer to 42-50%, and nut productivity by almost 1.5 times.rease the potential volume of the fruiting layer to 42-50%, and nut productivity by almost 1.5 times.

Impact of Working Environment on Job Satisfaction

Nowadays, different organizations and institutions are passing through challenges due to the fact of the working environment. For better job satisfaction working environment is considered as the prime factor to be considered by the employers. To keep the steady upward growth of the institutions it is mandatory to keep the efficiency, effectiveness, productivity of the employees by providing different facilities. And, working environment is the most crucial demand of the employees. Therefore, providing better working environment is also the prime concern of the organizations or institutions to maintain the steady workforce for the business to run. The objectives of this study are to understand the impact of working environment on job satisfaction by the quantitative and qualitative analysis of contributing characters. Data collections were done through a well-constructed questionnaire. The contributing populations were from two organizations named Department of Agricultural Extension and Bangladesh Rural Electrification Board. The sampling was done specifically from the one of the districts in Bangladesh. The study showed significant impacts of working environment on job satisfaction. As, without providing better facilities organizations can’t run properly, whereas- working environment is the prime concerning issue of the employee. Therefore, this study concluded as for the better job satisfaction working environment needs to be focused.

A Preliminary Implementation Framework of Building Information Modelling (BIM) in the Algerian AEC Industry

The construction industry is one of the most growing sectors worldwide, it plays a great role in boosting the economy. The construction sector in Algeria has recently witnessed an upward growth, due to the Algerian government’s vision to develop economic activity and boost the residential construction market. On the other hand, the Algerian construction market is suffering from the lack of efficiency; projects delay and less quality of projects delivery. It becomes very necessary to find a way to improve these inefficiencies by adopting new approaches and technologies. Building Information Modelling (BIM) is becoming a widespread and common approach in the design, construction and maintenance of building facilities as BIM reduces waste, improves construction quality and enhance collaboration among the construction stakeholders. Hence, it becomes necessary to start gradually introducing BIM to the Algerian construction industry in order to improve its productivity. This paper addresses BIM implementation in the Algerian AEC industry and proposes a preliminary framework towards its implementation. Through a questionnaire survey, we explored the BIM capabilities, BIM awareness and BIM maturity of the Algerian AEC players. Based on the questionnaire findings and literature review, this paper proposes an effective BIM implementation based on both levels of macro-adoption and micro-adoption. The framework developed is based on three main aspects comprise of technology, process and policy. This study is considered as the first implementation framework of Building information modelling in the Algerian AEC industry. The framework proposed will be used as a reference for the Algerian researchers and professionals.

An Analysis of the Journey of Open and Distance Education: Major Concepts and Cutoff Points in Research Trends

In an effort to understand trends in open and distance education more comprehensively, this study aims to identify the research trends, major concepts, and cutoff points in the articles published between 2009 and 2016. From five major peer-reviewed journals, a total of 989 articles were analyzed through a systematic literature review process using content analysis. The articles were coded based on the following three categories: level, topics, and sub-topics. The results indicated the followings: (1) emerged main themes in the articles were foundations of open and distance education, instructional process, and effects of applications; (2) there was an upward growth in the publishing of the articles on massive open online courses, open educational resources, and students’ perspectives; (3) new pedagogical approaches and online learning design played a triggering role in the research topics; and (4) technological and pedagogical developments between 2011 and 2012 had an influence on the tendency of the articles. In addition, we explored cutoff points so that they may provide insights and valuable hints for researchers to design new studies in open and distance education field. Discussions about the gaps in the state-of-the-art trends and directions about future research were also included.