Hydrochar can be used in many application such as of soil amendment, energy purposes, activated carbon adsorbent and nanostructured materials. Hydrochar has high stability buried in the soil, that can stand hundred or thousand years buried as a carbon sequestration. Additional hydroochar in soil gave many benefits that increased the crop yield. Hydrochar is porous material that absorb minerals and retain water, for sustainability supply of water. Addition hydrochar to the soil reduced the need of chemical fertilizer, resulting in reduced emissions from fertilizer production. Hydrochar increases the soil microbial life. Hydrochar retain of nitrogen, it will reduce nitrous oxide emissions. Turning agricultural waste into hydrochar, it will reduce methane generation by the natural decomposition of the waste. Hydrochar can neutralize the soil, but if the pH of soil already high addition of hydrochar increased the soil pH.........

KEYWORDS: hydrochar, soil, adsorb, nutrient, crop yield.

This study encompass the empirical data of the study carried out on compressive strength determination of Granite dust-Sandcrete building blocks with granite dust as partial replacement of three(3) grades of river sand with fineness modulus(fm) of 2.29, 2.44 and 2.89. The percentage replacements ranges from 0%, 10%, 20%, 30%, 40%, 50% to 100%. A grand total of 102 sandcrete blocks of 450 × 225 × 225mm metallic mould were blend, mixed and cast with a mix ratio of 1:5. Three(3) blocks were blend, mixed and cast for each percentage partial replacement and a total 34 blocks for each grade of river sand, were crushed to obtain the compression strength of 28th day curing respectively..........

KEYWORDS: Sandcrete, Granite dust, Cement, sandcrete Blocks, River Sand, compressive strength.

A model is developed to analyze the effect of axial conduction on heat transfer during single-phase flow in microchannels. The axial heat conduction in the wall introduces heat flow toward the inlet section resulting in an increase in the local fluid temperature and a corresponding increase in the wall temperature. Neglecting this effect while reducing the experimental data results in a lower value of the experimental Nusselt number. The model derived in this work takes into account this effect and offers a parameter to estimate the effect introduced by the axial heat conduction effect in the wall.

KEYWORDS: laminar flow, single-phase flow, model, axial conduction, heat transfer coefficient, microchannels

In this paper, Nusselt numbers for a power-law fluid in a fully developed laminar flow between parallel plates with constant, and different, wall heat fluxes in the presence of dissipation effects are presented. The Nusselt numbers values were obtained following two different approaches. One is the "classical" approach, based on a single bulk temperature, and this approach is used in this work to obtain for the first time generic analytical expressions for Nusselt numbers. In the new approach, different bulk temperatures are used for each Nu determination, one bulk temperature for each side of the location of the temperature profile where the derivative 0 T y    .

KEYWORDS: Convection, viscous dissipation, analytical solution, two bulk temperatures.

The asymptotic behavior of laminar forced convection in a circularduct, for a Herschel-Bulkley fluid with constantproperties, is analyzed by taking into account the viscous dissipation effects. The axial heat conduction in the fluid isneglected. The asymptotic temperature field and the asymptotic value of the Nusselt number are determined for every boundary condition that allows a fully developed region. Comparisons with other existing solutions for Newtonian and non-Newtonian cases are presented.

KEYWORDS:Asymptotic behavior, Herschel-Bulkley fluid, variable wall heat flux, laminar forced convection, viscous dissipation.

Photovoltaic (PV) systems can be grouped into stand-alone systems and grid-connected systems. In stand-alone systems the solar energy yield is matched to the energy demand. Since the solar energy yield often does not coincide in time with the energy demand from the connected loads, additional storage systems (batteries) are generally used. If the PV system is supported by an additional power source – for example, a wind or diesel generator - this is known as a photovoltaic hybrid system. In grid-connected systems the public electricity grid functions as an energy store.

KEYWORDS: Photovoltaic – Electric hybrid system - electrical grid - solar cells