the department of physics invites you to virtually attend a
final oral presentation by phys 4501 fde student:

sacha white
"factors influencing particle removal efficiency of mask filter media"

 thursday, april 29^th, 2021
time: 1:00 pm

_{(for zoom link and password email alinhana@lakeheadu.ca)}

the department of physics invites you to virtually attend 
final oral presentations by phys 4501 fde 世界杯2022赛程表淘汰赛

 noah kakekaspan
decomposing multiple copies of sp(2,r) into symmetrized irreducible representations

yamandeep malhi
optimization of image reconstruction parameters for positron emission tomography (pet) images
using maximum likelihood expectation maximization.

nathaniel oriecuia
development of attenuation correction for positron emission tomography (pet)
clinical images

anirudh shahi
signal pulse analysis in positron emission tomography for improvement in coordinate
reconstruction

 thursday, april 8^th, 2021
4:30 pm – 6:30 pm zoom

_{(for zoom link and password email alinhana@lakeheadu.ca)}

the department of physics invites you to attend a zoom seminar presented by:

dr. maryam ebrahimi
^{assistant professor & tier 2 canada research chair in low-dimensional nanomaterials
department of chemistry}

_entitled:

"surface-confined synthesis of molecular-based low-dimensional nanomaterials"

friday, february 5th, 2021
3:00 p.m. zoom event

 _{join zoom meeting
(to participate email the contact as listed below for the zoom link, login & password)}

_abstract:
the growing interest in low-dimensional nanomaterials stems from their remarkable properties, such as high electrical conductivity, heat transfer, mechanical and chemical stability, arising from dimension reduction. these exceptional properties have made graphene, the only 2d material in nature, the focus of significant academic research over the past two decades. however, the lack of an electronic bandgap limits its use in some electronic applications. this limitation has inspired the emergence of novel nanomaterials, such as self-assembled molecular networks, 2d polymers and covalent organic frameworks, towards constituting several prominent classes of organic analogues of graphene. [1] the chemical and electronic properties of these low-dimensional nanomaterials are determined by their morphology, dimension, size, building blocks, π-electron delocalization, and the chemical nature of the bonds held them together.

my research focuses on the on-surface synthesis of nanomaterials whose chemical and electronic properties can be tailored by their chemical structure. surfaces are used as a platform to design and fabricate ‘bottom-up’ materials made of organic molecules. [2] the molecules’ functional groups and the reactivity of the substrates control the molecule-molecule and molecule-substrate interactions. these factors, together with the surface planes, temperature, deposition rate, and coverage, steer surface chemical reactions; hence, control the design of the obtained molecular structures. i have adapted various surface reactions for the synthesis of molecular imprints, 1d and 2d polymers, metal-organic networks, and organometallic structures. [3-10] to identify their morphology and chemical nature, we employ scanning tunnelling microscopy and non-contact atomic force microscopy with atomic scale resolution, and other surface characterization techniques, such as x-ray photoelectron spectroscopy, complemented with density functional theory calculations.

the chemical, thermal, and mechanical stability, and structural design of these molecular-based low-dimensional nanomaterials make them promising candidates for various applications, from the adsorption of greenhouse gases for environmental applications, to harvesting energy and light. their unique tunable electronic properties, ranging from semiconducting to insulating behaviour, give rise to their integration in organic electronic devices used in displays, smartphones, and sensors. in summary, the molecular level understanding of the surface phenomena offers the pathway for the rational design of molecular networks and low-dimensional nanoarchitectures with tunable properties.

^{references
[1] m. ebrahimi, f. rosei, nature 542 (2017) 423-424 (news & views)
_{[2] d. p. goronzy et al., acs nano 12 (2018) 7445-7481
[3] m. ebrahimi et al., journal of the american chemical society 133 (2011) 16560-16565
[4] g. galeotti et al., faraday discussions 204 (2017) 453-469
[5] d. cui et al., journal of the american chemical society 139 (2017) 16732-16740
[6] f. de marchi et al., nanoscale 10 (2018) 16721-16729
[7] g. galeotti et al., chemical science 10 (2019) 5167-5175
[8] c. jing et al., angewandte chemie international edition 58 (2019) 18948-18956
[9] g. galeotti et al., nature materials 19 (2020) 874-880
[10] p. ji et al., small 16 (2020) 2002393}}

the department of physics invites you to attend a master of science thesis defense
presented by:

davide marchese
^{master of science in physics candidate}

 "study of a brominated triphenylamine derivative on metal and semiconducting surfaces"

^{_{supervisor: dr. m. gallagher
committee members: drs. g. das & h. de guise}}

date and time:

tuesday, october 13, 2020 from 1:00-2:00 pm

 join zoom meeting
(to participate email the contact as listed below for the zoom link, login & password)

department of physics invites you to attend a master of science thesis defense
(zoom event) presented by:

 navneet kaur
^{master of science in physics candidate}

 "tweezing and manipulating nanomaterials on tapered optical fiber to develop surface-enhanced raman spectroscopy (sers) substrate"

 _{supervisor: dr. g. das
committee members: drs m. gallagher & a. linhananta}

abstract:

a compact and cost-effective fiber-based probe was manufactured for the detection of chemicals at low concentrations using surface-enhanced raman spectroscopy (sers). multi-mode optical fiber was tapered with a dynamic etching process using hydrofluoric (hf) acid. the desired length, tip diameter, and cone angle of the tapered fiber were obtained by using this process. the sers substrate was prepared by depositing gold nanorods (gnrs) on the tapered fiber surface by the phenomenon called optical tweezing (ot). the tapered fiber was characterized by using a scanning electron microscope (sem) and optical microscope. light from a he-ne laser was coupled to the untapered end of the tapered fiber to study the distribution of gnrs using the optical microscope. the effect of different tweezing wavelengths, and the tapered length on the distribution of gnrs on the tapered fiber surface was investigated. it was observed that the maximum surface area of tapered fiber was covered with gnrs when tweezed consecutively with two different wavelengths (1064 nm and 632 nm). the application of the tapered fiber covered with gnrs as a sers substrate was investigated for two chemicals, rhodamine 6g (r6g) and graphite. furthermore, we presented the tweezing of a compound containing metal ion (zn2+) on the tapered fiber surface when mixed with gnrs solution using two lasers consecutively.

date and time:

friday, september 4th, 2020 at 1:00 pm

 zoom link:

time: sep 4, 2020 01:00 pm eastern time (us and canada)

join zoom meeting
(to participate email the contact as listed below for the zoom link, login & password)

department of physics invites you to attend a master of science thesis defense
(zoom event) presented by:

d. michael frood