An Elegant Method of Analysis for the BJT Amplifiers using Floating Admittance Matrix

The Floating Admittance Matrix (FAM) is an elegant, neat, illustrative, and simplified technique for analyzing all configurations of the BJT amplifiers, starting with the maneuvering of the FAM of the phase-splitter circuit. The conventional analysis method requires a small-signal equivalent circuit, and then conventional tools, either KCL, KVL, or Thevenin, Norton, etc., are used for the analysis. The researcher has to guess which conventional tool suites better than the other for any particular circuit, whether active or passive. The proposed technique is equally ell useful for all circuits. In the FAM method, once the device matrix is known rest of the circuit can be embedded in it by inspection. The sum property of this matrix provides a check to know whether FAM has been written correctly to proceed further.

Effect of Friction Stir Welding Techniques and Parameters on Polymers Joint Efficiency—A Critical Review

The objective of current work is to analyse the influence of different welding techniques and welding parameters on the morphology and mechanical strength of friction stir welds (FSW) in polymers, based on data collected in the literature. In the current work, only articles that provide data on the joint efficiency, or sufficient information to estimate it are considered. The process using conventional tool is presented and compared with new procedures developed for FSW of polymers, such as those using tools with heated stationary shoulder, preheating of the polymer or double-side passage of the tool. The influence of tool rotational speed (w), welding speed (v), tilt angle and geometry of the pin are discussed. This work focuses on the polymers most studied in the literature, polyethylene (PE) and polypropylene (PP). The use of external heating and tools with stationary shoulder proved to be of great importance in improving the surface finish, reducing defects, and increasing the mechanical strength of the welds. The increase in the w/v ratio increased the joint efficiency, especially when using conventional tools on PE. A trend was obtained for conventional FSW, but it was difficult to establish mathematical relationships, because of the variability of welding conditions.

An intuitive surgical handle design for robotic neurosurgery

Purpose The expanded endoscopic endonasal approach, a representative example of keyhole brain surgery, allows access to the pituitary gland and surrounding areas through the nasal and sphenoid cavities. Manipulating rigid instruments through these constrained spaces makes this approach technically challenging, and thus, a handheld robotic instrument could expand the surgeon’s capabilities. In this study, we present an intuitive handle prototype for such a robotic instrument. Methods We have designed and fabricated a surgical instrument handle prototype that maps the surgeon’s wrist directly to the robot joints. To alleviate the surgeon’s wrist of any excessive strain and fatigue, the tool is mounted on the surgeon’s forearm, making it parallel with the instrument’s shaft. To evaluate the handle’s performance and limitations, we constructed a surgical task simulator and compared our novel handle with a standard neurosurgical tool, with the tasks being performed by a consultant neurosurgeon. Results While using the proposed handle, the surgeon’s average success rate was $$80\%$$ 80 % , compared to $$41\%$$ 41 % when using a conventional tool. Additionally, the surgeon’s body posture while using the suggested prototype was deemed acceptable by the Rapid Upper Limb Assessment ergonomic survey, while early results indicate the absence of a learning curve. Conclusions Based on these preliminary results, the proposed handle prototype could offer an improvement over current neurosurgical tools and procedural ergonomics. By redirecting forces applied during the procedure to the forearm of the surgeon, and allowing for intuitive surgeon wrist to robot-joints movement mapping without compromising the robotic end effector’s expanded workspace, we believe that this handle could prove a substantial step toward improved neurosurgical instrumentation.

The role of ultra-sensitive molecular methods for detecting malaria – the broader perspective

Ultra-sensitive molecular diagnostics are lowering the limit of detection for malaria parasites in the blood and providing insights not captured by conventional tool such as microscopy and rapid antigen tests. Low-level malaria infections identified by molecular tools may influence clinical outcomes, transmission events, and elimination efforts. While many ultra-sensitive molecular methods require well-equipped laboratories, technologies such as loop-mediated isothermal amplification (LAMP) or recombinase polymerase amplification (RPA) provide more portable and analytically sensitive solutions. These tools may benefit asymptomatic patient screening, antenatal care, and elimination campaigns. We review the recent evidence, offer our perspective on the impact of these new tests and identify future research priorities.

BÖHLER K190 MICROCLEAN

Böhler K190 Microclean is a high-carbon, Cr-V-Mo, alloy cold-work tool steel that is produced by the powder metallurgy process. Compared to conventional tool steels, it exhibits a low inclusion level coupled with a highly homogeneous and fine-grained microstructure. It is used in challenging segments of cold work, where a combination of very high compressive strength, wear resistance, and toughness is required. This datasheet provides information on composition, physical properties, and hardness. It also includes information on heat treating and surface treatment. Filing Code: TS-810. Producer or source: voestalpine Böhler Edelstahl GmbH & Co KG.

A Design Insight for Substitution of Metal Shims with Reverse Engineered Element in Tool Post for Alignment of Tool-Work Center

This research work propounds and analyses the comparison of solution to the issue of height adjustment of tool in four way tool post. The customary way of tool lifting in tool post to centre of work i.e. by adding/removing metal packing, is altered by introducing a design alternative for tool lifting, an upgradation in the former proposed design named solid double cone threaded pin (SDCTP). It is explicitly studied to investigate its limitation and scope for further design amendments. In the premise, a revised design is proposed including modifications named as solid cone threaded pin (SCTP) and is fabricated along with its assembly. Mathematical calculations of least count and screw thread analysis are performed on both the pins. Finite element analysis on CREO is executed to calculate stresses induced for diverse loads to analyze pin failure conditions. The results of new modified design is compared with the erstwhile concluding that SCTP design is preferable over SDCTP design entailing precise tool adjustment, saving time and higher efficiency in machining operations. The paper subsequently explores conventional tool lifting method and its shortfall, shortcomings of former design, revised design and its comparison, fabrication of revised design, conclusions and future ambit.

Improving the Performance of EDM through Relief-Angled Tool Designs

Among the family of carbides, tungsten carbide (WC) and its variants have extensive use in numerous applications including cutting tools, dies, and many wear resistant parts. Such applications need machining of WC, which is famously considered as challenging due to high tool wear mainly in traditional machining. Sinking electric discharge machining (EDM) can be considered as a suitable alternate but the low machining rate of EDM, with conventional tool design, poses limitations. In this research, the conventional tool design is modified by providing relief angles to the tool electrodes. The relief-angled tool electrodes are first time introduced in this research to machine through holes. The role of the relief angle during EDM has been investigated in terms of six response characteristics, i.e., machining time, hole taper angle, radial overcut at the hole entrance, radial undercut at the hole exit, longitudinal tool wear, and roughness of inside hole surfaces. The performance of the relief-angled electrodes is found to be significantly better than the performance of conventional cylindrical tool. In addition to improvements in other responses, a 49% reduction in the machining time has been realized by the use of relief-angled electrode indicating a worthwhile contribution in the field of electric discharge machining.

Infrared renormalon in $SU(N)$ QCD(adj.) on $\mathbb{R}^3\times S^1$

We study the infrared renormalon in the gluon condensate in the $SU(N)$ gauge theory with $n_W$-flavor adjoint Weyl fermions (QCD(adj.)) on $\mathbb{R}^3\times S^1$ with the $\mathbb{Z}_N$ twisted boundary conditions. We rely on the so-called large-$\beta_0$ approximation as a conventional tool to analyze the renormalon, in which only Feynman diagrams that dominate in the large-$n_W$ limit are considered, while the coefficient of the vacuum polarization is set by hand to the one-loop beta function $\beta_0=11/3-2n_W/3$. In the large $N$ limit within the large-$\beta_0$ approximation, the W-boson, which acquires the twisted Kaluza–Klein momentum, produces the renormalon ambiguity corresponding to the Borel singularity at $u=2$. This provides an example that the system in the compactified space $\mathbb{R}^3\times S^1$ possesses the renormalon ambiguity identical to that in the uncompactified space $\mathbb{R}^4$. We also discuss the subtle issue that the location of the Borel singularity can change depending on the order of two necessary operations.

Rumus Hitung Eritrosit, Trombosit, dan Leukosit-Improved Neubauer

One (conventional) tool that is still used today to count erythrocytes, platelets and leukocytes is the Improved Neubauer chamber. This method is classified as a classic, but also very cheap, and easy to do in the examination of the count of blood cells. The counting chamber is specifically designed to count the number of erythrocytes, platelets and leukocytes with specific count zones. The area and volume of the zones used to count each cell tend to be different, requiring a separate formula