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Atmospheric pressure chemical vapor deposition (CVD) is presently a promising approach for preparing two-dimensional (2D) MoS2 crystals at high temperatures on SiO2/Si substrates. In this work, we propose an improved CVD method without hydrogen, which can increase formula flexibility by controlling the heating temperature of MoO3 powder and sulfur powder. The results show that the size and coverage of MoS2 domains vary largely, from discrete triangles to continuous film, on substrate. We find that the formation of MoS2 domains is dependent on the nucleation density of MoS2. Laminar flow theory is employed to elucidate the cause of the different shapes of MoS2 domains. The distribution of carrier gas speeds at the substrate surface leads to a change of nucleation density and a variation of domain morphology. Thus, nucleation density and domain morphology can be actively controlled by adjusting the carrier gas flow rate in the experimental system. These results are of significance for understanding the growth regulation of 2D MoS2 crystals.

In this study , three examples of failure analyses of electronic packaging by using the finite element method are presented. These are: (1) the failures (delaminations) near the interface between the filled copper and the silicon and between the copper and the silicon dioxide dielectric of the TSV of a 3D system-in-package (SiP) due to the local thermal expansion mismatch between the silicon and the filled copper; (2) the failures of the micro bumps between the fine-pitch IC chip and the TSV interposer (chip) due to the global thermal expansion mismatch between the silicon IC Chip and the copper filled TSV interposer (chip); and (3) the failures of leadfree solder joints of a wafer-level chip scale package (WLCSP) due to the thermal expansion mismatch between the silicon WLCSP and the FR-4 epoxy printed circuit board (PCB). The results show that finite element method is not only able to identify the failure locations and determine the stress and strain to cause failures but also perform design for reliability.

Mishrif carbonate formation is widely developed in Iraq and other areas of Middle East. When it comes to carbonate reservoir water injection development, the high heterogeneity commonly existed in carbonate reservoirs makes water flow complicated and performance of water injection differed from reservoir to reservoir. The existence of high permeability stripes and zones would make the problem more complicated and always result water early break through and poor sweep of the reservoir. Water injection pilots started recently in Mishrif carbonate reservoirs in M Field and N Field in southern Iraq. The objectives of these pilots were to investigate the feasibility to conduction water flooding in the Mishrif carbonate reservoirs, including test the injectivity and its change through time, sweep efficiency, responses from offset producers, investigate the methods that can be applied to tackle the problems brought by high permeability zones in water injection. The pilots were carried out in two different well patterns in the two fields, one is inverted nine spots pattern and the other is vertical-horizontal well pattern with vertical well as injector. In one pilot, separated injection was applied to avoid water channeling and improved producer performance. 3D numerical model was applied to track and monitor water sweep during the pilot. It was found out that directional connectivity and high permeability zones were developed in these reservoirs and resulted in early water breakthrough and quick increase of water cut in offset producers. This effect impact vertical and lateral sweep greatly and lower recovery potential in future field water flooding development if not well learned and handled. The challenges are to make description of these directional connectivity and distribution of high permeability zones in reservoir description and modeling and find effective ways in field operations to avoid the negative impact of them in field scale water flooding. To tackle the challenges, integrated reservoir study of multi-discipline is necessary in order to make full description of high permeability zones and reservoir heterogeneity and understand their mechanism on water sweep. It is suggested to pay additional attention to high permeability zone as a key factor in reservoir development of these kinds of reservoirs and integrated the study results into the design of field development plan in an early stage, to narrow the uncertainties brought by them and reduce development risks.