## 4 Conclusions
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Reference** & **Specifications** & **Remarks** \\ \hline  & & The thermal conductivity increased with both temperature and concentration. It was concluded that the increase with concentration was a result of greater surface area for heat transfer, and increase with temperature was a result of increased Brownian motion. \\ [PERSON] et al. (2016) & Nanoparticle Material: CuO & It was concluded that the difference in enhancement of thermal conductivity for each base liquid was caused by the variation in thermal conductivity of the base liquids, and differences in the strength of interactions between the nanoparticles and each base liquid. \\ [PERSON] et al. (2016) (2016) & Nanoparticle Material: Barometric Alumina & For all nanoparticle shapes, the thermal conductivity increased with the increase of volume fraction. \\ [PERSON] et al. (2016) (2016) & Nanoparticle Material: Nanodiamond, Co\({}_{3}\)O\({}_{4}\) & \\  & Weight Concentration: 0-0.15\% & \\ \hline  & Temperature Range (°C): 30-50 & \\  & Base Liquid: Hydrogenated Oil-based drilling fluid & It was observed that at low nanoparticle concentrations, the thermal conductivity improved by small amounts compared to at higher temperatures. \\ [PERSON] et al. (2016) (2016) & Nanoparticle Material: MWCNTs & It was observed that at low nanoparticle concentrations, the thermal conductivity improved by small amounts compared to at higher temperatures. \\  & Numeric Size (nm): & \\  & Outer diameter-12 & \\  & Inner diameter-6 & \\ \hline  & Temperature Range (°C): 10-80 & The thermal conductivity did not increase significantly with 0.01 V\% MWCNTs, but it did increase significantly with 0.03 V\%. \\  & Base Liquid: De-ionized Water & The thermal conductivity increased with \\  & Nanoparticle Material: Multi-Walled Carbon & The thermal conductivity increased with \\  & Nanotubes & temperature and particle concentration. \\ [PERSON] et al. (2015) (2015) & Particle & It was concluded that Brownian motion was the \\  & Nanoparticle Size (nm): & main contributor to the increase in thermal \\  & Outer diameter-30 nm Concentration (\(\varphi\)): & conductivity at high temperatures. \\  & 0.01\%, 0.03\%, 0.05\% & The MWCNTs/water nanofluid was very stable \\  & SDS & over time, making these nanofluids attractive \\  & & for applications in cooling. \\ \hline  & Temperature Range (°C): 10-70 & \\  & Base Liquid: Water & The thermal conductivity increased with both temperature and particle concentration. \\ [PERSON] et al. (2015) & Nanoparticle Material: FeC & The thermal conductivity increased with both temperature and particle concentration. \\ [PERSON] et al. (2015) & Particle Concentration (\(\varphi\)): 0.022\%, 0.17\%, 1\% & The addition of surfactant did not significantly \\  & Surfactant: Low Viscosity Carboxymethyl & The addition of surfactant did not significantly affect the thermal conductivity of the base fluid. \\  & Cellulose Sodium Salt (CMCNa) & affect the thermal conductivity of the base fluid. \\  & Surfactant Concentration: 3 g/L & \\ \hline  & Temperature Range (°C): 10-60 & The thermal conductivity enhancement \\  & Base Liquid: De-ionized Water & increased almost linearly with temperature and particle concentration. \\  & Nanoparticle Material: Short Single-Walled Carbon Nanotubes (S-SWNTs), long SWNTs & The addition of surfactant slightly reduced the thermal conductivity, but this reduction became \\ [PERSON] et al. (2015) & (L-SWNTs) and MWNTs & smaller with the increase of temperature. \\ [PERSON] et al. (2015) & Nanotube Lengths: & It was found that within the concentration \\  & S-SWNTs: 1-3 \(\mu\)m & range of 0.025–0.25 wt\% the addition of \\  & L-SWNTs: 5-30 \(\mu\)m/MWNTs: 30 \(\mu\)m & surfactant had a negligible effect on the thermal \\  & Surfactant: Hexadecyl Timethyl Ammonium & Surfactant had a negligible effect on the thermal \\  & Bromide (CTAB) & Conductivity. \\  & Concentration (\(\varphi\)): 0.05–0.48\% & The L-SWNTs were influenced most by the \\  & & change of concentration and temperature. \\ \hline  & Nanoparticle Material: Bohemite Alumina & For all nanoparticle shapes, the thermal conductivity increased with the increase of volume fraction. \\ [PERSON] et al. (2015) (2015) & Nanoparticle Shape: Rick, Platelet, Blade & Nanofluids containing brick-shaped \\  & Concentration (\(\varphi\)): 0.3–7.0\% & nanoparticles had the highest thermal \\  & Nanoparticle Size (nm): Brick-68.06, & conductivity enhancements, and those \\  & Platelet-58.77, Blade-21.22 & containing blade-shaped nanoparticles had the \\  & & lowest. \\ \hline  & & \\ \end{tabular}
\end{table}