Isolation of Thiobacillus spp. and its application in the removal of heavy metals from activated sludge

Two strains of Thiobacillus isolated from native excess activated sludge were identified as Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans by 16S rRNA gene sequencing and physiological-biochemical characteristics. Single and mixed cultures of the strains were used to carry out bioleaching for 9 days in order to remove heavy metals from activated sludge. The changes in pH, oxidation-reduction potential, and contents of heavy metals were measured. The results show that the bioleaching effect of the mixed culture was best in all runs, and that the final removals of As, Cr, Cu, Ni, and Zn were 96.09, 93.47, 98.32, 97.88, and 98.60%, respectively, whereas the removals of Cd and Pb decreased rapidly after six days. In addition, we demonstrate for the first time that bioleaching can reduce the pathogenicity of sludge by detecting fecal coliforms before and after bioleaching in order to ensure that the sludge was suitable for agricultural land application.Key words: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, excess activated sludge, removing heavy metals, sludge pathogenicity

Three-Dimensional Curvy Electronics Enabled by Conformal Additive Stamp Printing

The dominant form of electronics, i.e. microelectronics, have been traditionally manufactured into planar layouts. Many electronics and devices, ranging from optoelectronics to wave electronics and to wearables, need to be configured into three dimensional (3D) curvy shapes to realize their functions. However, so far, there has been very limited success in realizing them, mainly due to the lack of effective&nbsp; manufacturing technology. Here, we reported conformal additive stamp (CAS) printing technology for reliably manufacturing 3D curvy&nbsp; electronics in a simple and effective way. CAS printing employs a pneumatically inflated elastomeric balloon as a conformal stamping&nbsp; medium to pick up the pre-fabricated electronic devices and print them onto curvy surfaces. Various devices in curvy shapes, including Si&nbsp; pellets, photodetector arrays, electrically small antennas, hemispherical solar cells, and smart contact lenses are demonstrated based on&nbsp; CAS printing. CAS printing is versatile as it can manufacture onto arbitrary 3D surfaces. Systematic investigations have revealed the key&nbsp; aspects, fidelity, and versatility of CAS printing. CAS printing opens doors towards the burgeoning 3D curvy electronics.</p

Penyelesaian Tindak Pidana Perjudian yang Dilakukan oleh Anak Menurut UU No.11 Tahun 2012

The title of this legal writing is "The Completion of the Crime of Gambling Carried Out by minors based on the law Number 11 of 2012 on the Juvenile Justice system". This type of research is normative legal research. Normative legal research is a research conducted or focusing on norm of positive law in the form of legislation. Legal issues raised is whether the completion of the crime of gambling by children is in conformity with the law Number 11 of 2012 about the juvenile justice system. The purpose of this research is to determine and analyze the completion of the crime of gambling by children under the law of the juvenile justice system. The result showed that the efforts made to prevent criminal acts of a child is an attempt preventive and repressive efforts. Juvenile justice system is closely related to restorative justice. Regarding the obligation to make a diversion conducted by law enforcement officials, in particular under Article 7 and 96 of the law number 11 of 2012 on the Juvenile Justice System

Biaxially Stretchable Ultrathin Si Enabled by Serpentine Structures on Prestrained Elastomers

Building stretchable electronics from inorganic materials is a testified pathway toward devices with high performances for many applications in fields such as optoelectronics, biomedical, etc. Owing to the unstretchable nature of these materials (e.g., brittleness of Si), existing ways to enable stretchabilities mainly involve either bonding thin films on a prestrained elastomer substrate or configuring materials into thin serpentine layouts. It is hypothesized that a combination of prestrain and serpentine will lead to advantages in the: (1) enlarged stretchability at the materials and (2) enhanced areal fill factor of the materials, when compared with existing serpentine structures without using prestrain strategy. This paper reports a biaxially stretchable Si structure and its optoelectronic devices enabled through the combination of serpentine structure designs and prestrain strategy on an elastomer substrate. The detailed device design and fabrication, mechanical analysis, and electrical performance characterization illustrate the key concept and validate the hypothesis. The Si nanomesh can be stretched by 75% biaxially with prestrain of 50% and has an enhanced areal fill factor of 125%. The combined strategy of prestrain and serpentine is applicable to a wide range of materials and devices, and the demonstrated results can be useful for stretchable electronics, optoelectronics, and many others

Nylon Fabric Enabled Tough and Flaw Insensitive Stretchable Electronics

The architecture of stretchable electronics, typically in the fashion of very thin functional electronics on a stretchable rubber substrate, defines their mechanical robustness which is dominantly attributed to the stretchable rubber substrate. Most of the existing and reported stretchable electronics are vulnerable to flaws or cracks in the substrate and subject to fracture upon mechanical deformation, which limits their practical usages. Here, a class of tough and flaw insensitive stretchable electronics enabled by a Nylon/rubber composite substrate is reported. The woven and stretchable fibers in the Nylon fabric are responsible for its high toughness and flaw insensitivity, as they prevent crack propagation by dissipating the energy into the nearby fiber network and also the rubber matrix to yield enhanced toughness and flaw insensitivity. Stretchable electrodes, supercapacitors, and photodetectors with high toughness and flaw insensitivity are developed as examples to illustrate the validity of such a type of stretchable electronics. Systematic studies of the associated materials, fabrication, mechanical and electrical properties, and reliability illustrate the key aspects of such a type of stretchable tough and flaw insensitive electronics and also suggest routes toward stretchable electronics with other functions

Crack-Insensitive Wearable Electronics Enabled Through High-Strength Kevlar Fabrics

Mechanical robustness is one of the key factors for future commercialization of wearable electronics. Wearable electronics are thin electronics constructed on flexible polymer or rubber substrates. Due to their thin geometry, wearable electronics are typically vulnerable under tearing or stretching, especially when cracks exist. This paper presents the designs and manufacturing of crack-insensitive wearable electronics realized through incorporating high-strength Kevlar fabrics. Manufacturing strategies of transfer printing prefabricated electronics onto Kevlar fabric with adhesion layer and dip coating constructed devices have been illustrated. The device examples include ultrathin single-crystalline Si-based photodiodes, organic photodetectors, and carbon nanotube-based supercapacitors. Systematic studies highlight the fabrication procedures, mechanical characterization, and device performance evaluation, and offer practical routes to realize robust crack-insensitive wearable electronics

Mechanically flexible microfluidics for microparticle dispensing based on traveling wave dielectrophoresis

Transdermal delivery has emerged as an attractive drug administration approach. A soft flexible transdermal delivery device that can dispense drugs in an on-demand and controllable manner is promising for healthcare. Here we report a mechanically flexible microfluidic device with on-demand and controllable dispensing capability based on traveling wave dielectrophoresis (twDEP). The device is an integration of a microfluidic channel for microparticle transport and an interdigitated electrode array for phase-shifted electric field generation. Microparticles are used to mimic drug molecules. The twDEP provides a feasible mechanism for microparticle transportation. The on-demand dispensing is achieved upon the application of alternating current (AC) electrical inputs. The dispensing flow velocity controllability lies in the amplitude and frequency of the applied AC potential. The demonstration of controllable microparticle dispensing in the mechanically flexible microfluidic device suggests its usage for transdermal drug dispensing through optimization based on drug properties and integration with drug storage and release components. ?? 2020 IOP Publishing Ltd

Destructive electronics from electrochemical-mechanically triggered chemical dissolution

The considerable need to enhance data and hardware security suggest one possible future for electronics where it is possible to destroy them and even make them disappear physically. This paper reports a type of destructive electronics which features fast transience from chemical dissolution on-demand triggered in an electrochemical-mechanical manner. The detailed materials, mechanics, and device construction of the destructive electronics are presented. Experiment and analysis of the triggered releasing and transience study of electronic materials, resistors and metal-oxide-semiconductor field effect transistors illustrate the key aspects of the destructive electronics. The reported destructive electronics is useful in a wide range of areas from security and defense, to medical application

Transient thermo-mechanical analysis for bimorph soft robot based on thermally responsive liquid crystal elastomers

Thermally responsive liquid crystal elastomers (LCEs) hold great promise in applications of soft robots and actuators because of the induced size and shape change with temperature. Experiments have successfully demonstrated that the LCE based bimorphs can be effective soft robots once integrated with soft sensors and thermal actuators. Here, we present an analytical transient thermo-mechanical model for a bimorph structure based soft robot, which consists of a strip of LCE and a thermal inert polymer actuated by an ultrathin stretchable open-mesh shaped heater to mimic the unique locomotion behaviors of an inchworm. The coupled mechanical and thermal analysis based on the thermo-mechanical theory is carried out to underpin the transient bending behavior, and a systematic understanding is therefore achieved. The key analytical results reveal that the thickness and the modulus ratio of the LCE and the inert polymer layer dominate the transient bending deformation. The analytical results will not only render fundamental understanding of the actuation of bimorph structures, but also facilitate the rational design of soft robotics